Welcome to the .org Lyberoc.

First question: Just take a diplomat and drop him on the man who has the title you wish to remove. A remove title parchment should appear then click the seal that has a check mark in it. The title will then reappear on the map ready for reassignment.

Second question: Only certain catholic factions can crusade. English, French, Hungry, Italy, Spain, and the HRE are the only ones that can crusade I believe.

Third question: One way is to take a very low loyaltly general and place him far away from your king with alot of troops. Another is to sent you king to an Island and then cut the ship link back to the mainland, this can start one. One thing about civil wars is that their is no sure way to get one. Just keep playing and they seem to pop up when unwanted and at all the wrong times.

Good luck mate