Luke 17:21b (King James Version) The kingdom of God cometh not with observation:
"Christianity" is a relationship not a "religious" set of rules to follow. This becomes an ocean of discussion.

Belief in God = Agreeing with Him, it has little to do with evolution and as a complete theory it is not Scientifically proven. I don't see a problem even if it were though. Yet another ocean of discussion you have here.
Dinosaurs are a small side tangent on the last thought. Biblically, there were a couple large animals that possible fit their descriptions.
The enemy/devil wanted to be God, is basically jealous of humans, is not in hell yet, only wants to deceive us so we can not receive God's unconditional love, so he can possible rob God of those He loves and He really does not believe he can fail because he is twisted by his own lies.
Humans were designed to live in the manifest universe and the idea is we will spend most of our eternity here. If you are actually interested in Heaven itself knowing that, it is yet another discussion.
Have you ever considered, trying to pinpoint exactly what you should be asking?