1: I don't start work until the commission is marked payed (not including the rough character image, i start trying to figure out what you want straight away)
2: I'm generally ok with NSFW things but it could cost extra biased on how complex you want it (more characters; "goostuff")
3: Be explicit what you want the character to look like, animation takes a long time (i will send you rough sketches to be sure what you want, but be fair with how many revisions you want)
4: Again, it's animation so be realistic with your expectations in terms of character complexity