Yes, I feel that wide-grip chins will aggravate the rotator-cuff moreso than any other back exercise. Especially if you let yourself go all the way down and "relax" your shoulders at the bottom of the movement. Some people can do them without injuring themselves, but I don't think they are worth doing over palms-facing pullups. IMHO, of course. If you like them--keep doing them.
Two, a bent-over row does not necessitate a 90 degree bend at the waist. That is just asking for a lower back injury #1, and number 2 -- you have next to no leverage in that position. 30-40 degrees is as far as you need to go for maximum upper back/lat involvement. Just my 2 cents.