i am curious what the rotator cuff exercises are...as i think that is a problem for me, too. i have t.e. and have been off six weeks or so. actually, the desire wanes a bit, and i have substituted several things in its place...jogging, weight room, golf. am going to p.t. and have a few more weeks til i see the doctor. no pain, now, really. strength seems better. my pt is working me on grip strength, too, which i think is going to help. seems all these muscles act as your suspension/springs...and the more strength, the less each individual muscle has to carry. and like a chain, it breaks at the weakest connection.
do give it a rest, it was REALLY HARD to quit, but in one sane moment, i got subs for the entire summer and am now just strengthening. i know my game will suffer, but what can ya do?
i plan to start from the beginning once i do start, and try to reduce some of my poor form. i, like you, have pain in the serve. i like some of the tips here,
anyway, good luck, keep us posted, and let it heal!!