Evangel, I would like to comment on #1:
"1. If God is one, what is the trinity? How does it work? How are three separate entities one? How do they all have different purposes and are one? How does the trinity work, while still being monotheistic (Belief in One God alone)"
I would like to share how I understand the Trinity using the law of first mention. Doing so will take care of most of the questions raised in objection to the concept of the Trinity (I believe).
There are three kinds of intelligent beings: The Godhead, the angels, and Human Beings.
1. In the Godhead there are three separate persons: the Father, the Son and the Holy Spirit.
2. In the angelic realm you have God's angels and then there are the fallen ones called demons.
3. In the human realm you have Adam and Eve and all their offspring of which we are. (Unless you claim to have descended from some primate!)
Consider the language used in Genesis 1 concerning the creation of man: "26 Then God said, Let Us make man in Our image, according to Our likeness;" Us - plural; Our - plural - more then one.
Verse 27: "God created man in His own image, in the image of God He created him; male and female He created them." God made two beings in his own image - two human beings. They were separate beings - him and her.
From these verses I gather that God exists in different beings. They are not one in the sense of one creature.
If you consider this carefully, verses that refer to the Believers as being 'one as we are one' will make more sense. John 17:11, 21,22. Jesus prays that the Believers be One as he and the Father are one. He is talking about unity in purpose, mind and thought. The Believers were not to be one physical entity, but one in goal, purpose - a unity. The concept of 'one' in the rest of the scripture refers to UNITY in purpose, mind.
Another example is the husband and wife relationship. They are to be one. Matthew 19:5; Mark 10:8; Eph. 5:31. My husband and I are still two different persons with two different bodies. From my observations this is true of all humans that I know. But in life, work, mind we are to be unified. I know my husbands mindset, how his mind works, what he thinks and does not think. I know what pleases him or displeases him. And the same with me. But we have two different bodies, very different. We also have different responsibilities in life, but all complementary.
If this concept is understood it will answer a lot of critics accusations although I do sense that many do not even want to understand this!
I shared this with a JW one time and they acted horrified! They said you believe there are three gods? Now what do you say to that? Actually, most of these critics are not interested in the TRUTH - all they are interested in is destroying your faith and they work to do so by finding inconsistent loopholes in Christian theology.
I will refrain from quoting more scriptures defending this concept. I think if the concept as revealed in Genesis 1 is understood, the rest will all fall in place real easy. Simple, in my opinion.
Hope this makes sense.