OK here we go:
Tannen Tamer: First move Right, then Jump to move the box, move Right again and Jump again to move the box into possition, then just, move Right and Duck to get Biff in 6 jumps.
Demystifire: This one is real easy. Just go to the flophouse and talk to Doc. Ask him about 'Run This Through For Me...'. And he will explain each of the different timelines we made.