There will always be taps. It's thumps that we want to avoid. If two cars go through a corner together, and they tap each other side-on, this isn't a problem as long as the 'tapped' isn't slowed or destabilised in any way, or nudged off the exit racing line. If I am on the inside and there is contact, generally I would not press any advantage through the following section, unless I have a clear straightline speed advantage - I would either hold position alongside, or concede place.
Last-ditch diving in the braking zone is fine by me, but the dive must be completed in a timely fashion, and the corner 'won' before the turn-in. If the inside car is fully alongside, both cars may proceed together but give each other enough room, respecting each others' positions - even through a chicane. If the diving car leaves it late and outbrakes himself slightly, so that he goes deep right at the outside car's turn-in point (thus blocking his turn-in) then this counts as careless driving (which we've all done).
Late diving is very risky in such big heavy cars, and I generally avoid this. If I want to pass someone, I'd aim to perfect the preceeding section, nail the exit of a corner, and get a better run, getting closer to the guy in front before the next corner. If there are two guys in front battling, I'd wait for them to space out a bit before attempting to pass them one by one.