Russ, I think dry-sumping also helps with oil cooling (more oil capacity) and surge problems (it isn't thrown around the sump during cornering and acceleration/braking).
Pretty much as you both said really. To get the engine lower & further back to aid cg and weight distribution. Also, to stop oil surge as this is going to get driven hard and tracked.
The Q intake is no concern as it's going in the bin - using 8 45mm throttle bodies on runners instead.
You also make more power as the crankcase is run at a vacuum so there's less air in there to pump around as the pistons move in the bores. Good for fixing oil leaks too
Oh yes I also remember reading in John Lingenfelters book something about if the crank isn't in an oil bath that's good news as well as it just wastes power chucking it about. Something along those lines.