1. Crucifixion is certainly a gruesome way to die. However, Jesus saved me from something far worse. An eternity in hell as punishment for my sins. If a person saved your life by pulling you out of a burning house, you would be forever thankful. I have that same gratitude to Jesus.
I would be glad that I was pulled from the house. But in this analogy the person pulling me from the house would be the same person that set it on fire and put me in the house to begin with. So I certainly wouldn't be grateful.
2. I understand your point. However, you're not God. Here's a human comparison that will have some exceptions. When we were children, most of our parents gave us specific commands because they wanted the best for us. God's the same way, just on a much higher level.
None of the parents I know who love their children would ever create a place of eternal damnation with no hope of redemption and send their kids their as a punishment for not believing in them (or as punishment for anything else).