concerning rear derailler, i had a problem with mine too ,changed gears to go up and all of a sudden, the derailleur fuller retracted and went right between the spokes in the rear wheel (luckily i was just testing the bike because i changed the pads earlier in the day,or else i would have been pretty mangled up lol) what could have cause the problem ?
btw the derailler is all bent now but the wheel stayed true (weird) made a quick single speed mode to save the ride day!