I will not answer that question because all I have right now is my opinion. But, I will pose another. Do you have to have children to be an elder? If you must be married, must you have children?

Finney says this:

"XVI. EVILS OF CLERICAL CELIBACY.

1. It is a war with nature.
2. It is a bad example, and encourages it in laymen.
3. It tends to licentiousness. This is a notorious fact.
4. Celibates cannot rebuke celibacy in laymen.
5. It is unjust to women.
6. Reproaches God, and implies a denial of his wisdom.
7. It is a constant temptation to unchastity.
8. It makes chaste women afraid of them.
9. It makes them a temptation to many women.
10. Makes them the terror of husbands.
11. Creates much jealousy in families.
12. Many do have and will have mistresses notorious (??).
13. Make the clergy generally odious.
14. Also, objects of suspicion.
15. Expose them to endless female intrigues.
16. Makes them selfish and unsocial.
17. Begets a contempt for women.
18. Corrupts society. This is a fact, see Catholic Europe.
19. It embarrasses them in their work in many ways.
20. Renders them incompetent to be a spiritual guide to females.
21. It embarrasses their spiritual development.
22. It is an error of the same class as nunneries and monasteries. It grew out of the idea that sin has its root in matter, and that the body is essentially impure, that its appetites must be annihilated.
23. Trial has demonstrated that the celibacy of the clergy is only evil continually.
24. Never justifiable except for the most cogent reasons.
25. As the reasons can't be generally made public, it falls under the rule, 'do nothing that needs explanation when such explanation is impracticable."
-"Lecture Notes On Pastoral Theology", pp. 45-46, Published by Richard M. Friedrich, 2002


"XIII. MARRIAGE OF MINISTERS.

1. Marriage a divine institution.
2. The rule, and celibacy the exception with all.
3. Also, the duty and the privilege of the human race.
4. Ministers are no exception. See objections to minister's celibacy.
5. They eminently need wives.
6. They need a wife to protect them against temptation.
7. Also, against being a snare to women.
8. To secure them against suspicion and jealousy.
9. They need the sympathy and the prayers of a wife.
10. They need the knowledge of woman which they get by having a wife.
11. Also, the counsel of a wife.
12. Also, the help of a wife, to understand the wants, trials, and infirmities of women, and their sins.
13. Also, to view things through a wife's eyes, and from a woman's standpoint.
14. To be an example as a husband.
15. Also, as the head of a family.
16. To give one the experience of a husband.
17. It makes him seem more like one of the people.
18. It allies him more closely to society.
19. Creates a bond of family sympathy between him and other families.
20. It gives him a higher conception of God's wisdom and care for human happiness.
21. Makes him better acquainted with human nature, human wants, excellencies, defects.
22. A single man is not a whole man.
23. Not generally a happy or a safe man, as pastor.
24. Apt to be selfish, prejudiced against women.
25. Also incompetent as a teacher of women.
26. As the church is composed mostly of females, celibacy, if prolonged, is a serious drawback.
27. Ministers should honor marriage by example.
28. They should, in every way, discourage celibacy.
29. To decline marriage, is to indirectly encourage licentiousness.
30. Also, to wrong woman, dishonor God.
31. Celibacy justifiable only for peculiar reasons.
32. Priestly or ministerial office no justification of celibacy."
-pp. 38-39

Also:

"XV. PAPISTICAL REASONS FOR PRIESTLY CELIBACY.
1. Marriage embarrassing to the spiritual life. Answer:
(1) It is a help, as it prevents temptation.
(2) It cultivates many forms of virtue.
(3) It is in accordance with our nature.
(4) It is a necessity of the race, and its continuance.
2. Inconsistent with the example of Christ and Paul.
Their example justified by peculiar reasons.
3. Paul wished that all men were unmarried. Answer:
(1) This, if it proves anything, proves too much.
(2) The wish was the result of the peculiar circumstances of the church at the time.
4. Paul's teaching and example imply a disapproval of marriage. Answer:
(1) Not more so of priests, than of all.
(2) Paul guarded against this inference by expressly declaring marriage honorable in all, ministers and people.
5. Revelation represents those "who have not defiled themselves with women" as being more highly honored in heaven. Answer:
(1) Whatever this means, it is not peculiar to ministers.
(2) The intercourse of the married is not defiling.
(3) The passage has reference to fornication and adultery.
(4) Paul considered marriage, with its duties and privileges as not defiling the bed.
(5) Paul denounced "forbidding to marry."
6. It is better for the spirit to deny and crush the flesh.
(1) Then our animal nature is a mistake.
(2) Then we are justified in not propagating the race.
(3) Restraint within divinely appointed limits, and not the utter denial and annihilation of our constitutional appetites, is our law.
(4) Enoch walked with God 400 years and begat sons and daughters.
7. A family is a hindrance to a minister in his work. Ans.:
(1) This is exceptional. The reverse is the rule.
(2) If this were a necessary result, it should have prohibited the marriage of apostles and ministers.
(3) Paul asserts that he and Barnabas were at liberty to marry.
(4) A well-ordered family a constant help to a minister in many ways.
(5) The help more than counterbalances the hindrance.
8. A single man is less expensive to the church. Answer:
(1) No minister at all would cost less still, in dollars.
(2) But to do without a minister would be too expensive.
(3) Churches can't afford to be without a whole pastor.
(4) A pastor's wife more than pays for her support.
(5) It is a shame for the church to take this view.
(6) This is seriously urged by the ritualists of England today.
(7) Especially as it respects curates and the lower clergy.
(8) They plead for an expensive clergy for the upper classes.
(9) And hence, for celibacy of the lower clergy, because they will be less expensive to the people.
(10) A minister can often keep house as cheaply as he can board - his garden, fruit, washing, and mending.
(11) Most congregations can pay him easier in the products of their industry.
(12) It is generally dangerous for a minister to board. It creates jealousy of the family in which he boards.
(13) Also, the woman where he boards.
(14) He needs the sacred enclosure and confidence of his own family."
-pp. 42-44

I think this all applies to elders as well but maybe I am wrong.

Other Commentaries on Titus 1:6 concerning "the husband of one wife." All come from www.searchgodsword.org

"Husband of one wife ...
There can be no doubt that heads of families were alone considered suitable material from among whom the appointment of elders was to be made, as indicated by the entire context. The historical church sinned in the development of a government by celibate priests. This qualification does not allow an elder to be polygamous, nor to be divorced and remarried except upon Scriptural grounds."
- Coffman Commentaries on the Old and New Testament

"There is his relative character. In his own person, he must be of conjugal chastity: The husband of one wife. The church of Rome says the husband of no wife, but from the beginning it was not so; marriage is an ordinance from which no profession nor calling is a bar. 1 Co. 9:5, Have I not power, says Paul, to lead about a sister, a wife, as well as other apostles? Forbidding to marry is one of the erroneous doctrines of the antichristian church, 1 Tim. 4:3. Not that ministers must be married; this is not meant; but the husband of one wife may be either not having divorced his wife and married another (as was too common among those of the circumcision, even for slight causes), or the husband of one wife, that is, at one and the same time, no bigamist; not that he might not be married to more than one wife successively, but, being married, he must have but one wife at once, not two or more, according to the too common sinful practice of those times, by a perverse imitation of the patriarchs, from which evil custom our Lord taught a reformation."
- Matthew Henry Complete Commentary on the Whole Bible

It's intersting that there are much fewer expositions on this part of the verse. And I could find nothing about "having children" as was mentioned but only comments as applied to the entire phrase "having children who believed." That is a very intruiging question.
It seems pretty clear to me that Paul directed that all elders must be married to one wife. He could have said "only one wife" but he did not do so either here or in 1 Timothy 3:2. I feel the same goes for having children. Paul could have said "And if having children, they must believe (or "be faithful")" but he simply said "having children who."
This is merely my opinion as it's not made totally clear. I simply consider Paul's guidlines here as wise council. If I were ever in a place where I was to make such a decision, it would have to be for some peculiar reason that, one who does not fit these categories as I understand them, would be accepted as an elder.
It seems that on many of these kinds of things they are not made completely clear. Therefore, we have need of the Spirit's guidance in each situation.

Is there an age requirement for an elder? Is he an elder just because he is old and met all the other requirements, or because he knew his word, regardless of his age. There is a natural progression of the older the person, the more chances they have had to study.

On the same topic, I feel that as a minister, God would have allowed for me to remain single. It was not wrong for me to remain celibate, nor was it wrong for me to get married. For myself, on my way to marriage, it will make me lean on God more than being single would. However, God had to bring that person into my life that was called the same way I was. Had I married someone who was not, that would have been wrong. Everytime I make a decision now, I think of her. Not in a bad way, but I do have someone else to think of. Being single would have made me do it out of sheer willpower, rather than God's grace. Getting married will make me depend on God more.

However, if you want to be single, more power to you. (If God has called you to that)