If I change my pitching mechanics?

I've been throwing in the 3/4 arm slot  for a while with mild sucess but I've been throwing at a higher arm slot lately and my pitching motion is more fluid and my velocity has jumped a little but are there any repercussion of me doing that? Then is it better to work out of the stretch or wind up I've been mainly pitching out of the wind up (my wind up is kinda like Tim Lincecum's) and if I switch to the stretch will I be horribly messed up? Then I have a FB/CU/SLU/CUT pitch mix people say a slurve is just a bad slider so should I drop it? Thoughts anybody?