When it comes to Questions to ask the players during Character Creation I often add this one.
“What limits does your character have?”
Especially if a player makes a character that have violent streak. Some players have the urge to create characters that has few limits and weaknesses since these can put them in problematic situations and tough moral choices.
So I ask, “What limits does you character have?” Then specify it if I feel that it is needed: Violence? Sex? Drugs? Dignity? If it is hard for them to figure it out I ask more specific questions to home in on it.
“Have you ever hurt or killed someone?”
“What do you think about cheating?”
“What do you care about?”
“What would you do if…?”
“Would you ever…?”
Test this on your players when they create their characters to lure out some more depth and humanity.