> does He want us to all be Christian?
Yes, He does. If we are assuming the Abrahamic God actually exists, that's a very profound reality and a life-altering truth. To not conform to that truth is sort of the ultimate missing of the mark.
> Why did he take so long to reveal himself, from the first humans to the first Jews (who incidentally weren’t monotheistic), to allegedly coming down from Heaven as Himself/His Son?
There is value in process. Process is how we best learn. Time, experiences, observations, and learning are how we are formed as people and where wisdom comes from. If God just dumps knowledge into our heads, we don't actually learn anything. We become lazy and actually quite stupid because we never have to work at it.
> If He does want us all to be Christians, why did He choose such a flawed book as the Bible
The Bible isn't flawed, but this is a discussion all its own, isn't it.
> why did he choose an ignorant tribe of goat herders to disseminate His Word?
I think you may be confusing non-literate with stupid. Actually, we look back to ancient societies with great respect. We still don't know how they built the Great Pyramid or Stonehenge. They were able to figure out astounding things. In many ways, I wonder if they were smarter than many people in our culture who have book-learning but don't know the first thing about the world and about how to fix things. Some of the greatest literature the world has ever known comes from "goat-herders" like David, or Homer, or some Greek philosophers.
> Why choose a miracle such as raising himself up to “save humanity” rather than any other method of actually saving us and/or proving to us that He exists?
Miracles were just signs. And, by the way, the resurrection was done in a way to prove that He exists. He could have just disappeared from the tomb and left the disciples to assume He had raised, and then preach about their blind faith. But that's not what He did at all. He showed Himself, talked to them, let them touch Him, ate food in front of them—all evidences (look at Acts 1:3). He proved Himself to them. Now, 2000 years later, we have to assess the reliability of the written record that is there for us to evaluate. But we have brains; we should be able to handle it unless we are goat-herders or state-university students
> Why create humans to be these interesting, complex creatures with a wide array of talents, interests, beliefs, practices, ethnicities, sexual identity, gender identity, language, culture, etc.... and then say, “Naw. I’d really like you all to believe and behave EXACTLY THE SAME WAY”
Truth is narrow. Do we really all have to believe that the sun is a ball of burning gas? Do we really all have to subscribe to the idea that pi is 3.14159...? Aw, c'mon! In all the complexity, why do we all have to believe and behave exactly the same way???? It's because we subscribe to the truth, and truth is narrow. We can all guess all we want about who shot JFK, but once the truth comes out (if ever), all theories will go by the wayside except the ONE that's true.
> Why not just create us all to be white, hetero Greek speaking Jesus freaks if that’s what He wanted?
It's not what He wants. It's pretty obvious that God values diversity, and so should we. But that doesn't mean truth can be whatever we want it to be. But it does mean that we are one beautiful diverse world and a wonderful agglomeration of diverse humanity.
> Why allow Jewish culture to develop and thrive, only to say “actually, that’s all wrong— you’re supposed to believe in THIS kind of Messiah now and adopt these entirely new Christian practices”.
Jewish culture veered off the road not because of a flaw in the revelation but because of their own human flaws. Someone was just commenting to me today (who is reading through the Bible and is up to the 4th book, Numbers): "You know, for being God's chosen people, the Israelites were pretty terrible... after seeing God’s blessing countless times they still didn’t believe. It’s astonishing to me, not only they turned their backs so many times, but that God didn’t turn His back to them." Yep. People can be quite stupid, even those who see the truth right in front of their noses.