When I'm by myself, I'm dashing and sassy: two in one.
If you exchange my right for left, then your sticks and stones may hurt my skin.
Remove one of my parts and I'll be dependent on you, but you won't mind.
Changing my tail can change my appearance; that can be an extra benefit.
If I was as plush as a Beanie Baby, I might be wildly attractive.
Add a double letter and jostle me about, and I'll annoy you.
Switch one of me with its successor and I'll annoy you more.
Switch another one of me with its successor and you may stumble backwards.
Turn me around, cut off my head, figure me out and be rewarded.
Substitute me for an imminent part and I am essentially me inside me.
What am I? What ten other things did I transform into?
PRETTY and IMPERTINENT are due to suggestions in comments from MOehm and Hugh Meyers. (PRETTY is (PERT+TY)*, and IMPERTINENT is IMMINENT with one M replaced with PERT.) And TWERP is following a hint from Rubio himself in the comments. W is a double letter, don'tcha see?) I was in some doubt about these until confirmed by Rubio in comments :-).