Beginners mistake with the SVT when shifting hard is to confuse reverse with 1st gear. First time I tracked my car, I downshifted from third to second, and couldnt get in.. Turned out i was just pushing a bit to hard to the left. That could be it.
As for the chatter, thats a stock clutch thing, I thought they took care of that with the newer clutches, but maybe they didnt. Most guys I know with the OE clutches dont have the problem anymore.