I don't take rest breaks, I give the weights a rest. Haha no really I've been lifting for so long that I do everything by feel. Some days I need liner rest periods and other days it's very limited rest. It also varies for between each set. Just listen to your body and embrace the mind/muscle connection.
Depends. The heavier weight I work up towards, the longer the rest break needs to be in order to get a quality set. The overall goal is always to keep them as short as possible without hindering performance.