Being too young, well at this point that just may be moot. I will answer the Q's. You can use a 1" no problem unless you are blatantly FAT.

I use 22G 1-1/2" so I go deep. Sometimes I get sore, too sore because of the frequency I pin so I'll use a 23G 1" for my glutes.

Shoulders for me w/water base 25G 5/8" in my quads I use a 23G 1" . ...crazy mike