Yeah, youre probably right about the heads - It is a longshot that both are warped.....BUT, what about the lower intake? Specifically where it mates to the heads. If you have the top-end all apart, might as well check all surfaces for straightness.

For the PCV, I'm not sure what you could use. One thing for sure is that boosted engines need SPECIFIC types of ventilation for the crankcase - If you run a regular PCV you might end up getting oil "shot" into the intake through the PCV when your block is pressurized (under boost). Also, running an open breather might cause your engine compartment to be covered in a film of oil because of the pressurized block thing, but this is more of a nuisance than a serious concern.

As for the rings, Ive never heard of that much consumption while seating. I don't know who your machinist is, but if the cylinder wasn't bored perfectly "square" then your rings won't seat properly at all. Moly rings especially need a perfectly bored surface as opposed to regular cast rings.

Gapless rings aren't really an option, theyre only good on low performance applications, on high compression engines - and specifically boosted engines - you get ring flutter...Not good at all.

The only boosted car Ive ever owned is my current factory turbo car, so I'll try and relate.
For block pressure, well, it has enough pressure build-up in the block that the rubber-sealed dipstick pops out.... And this is all how it was engineered from the factory, it runs as perfect as it should.
The PCV is specific, it has a valve in it that (supposed to) avoids any oil going past it, and also avoids the tendancy for oil to shoot past it when you suddenly come off boost. It leads into the intake tube (air cleaner box) which supplies the vaccuum, which still manages to gets some oil in it, but still works as good as one can expect.

Thing is its acceptale for boosted cars to have some oil burning and some blow-by, but yours is too excesive (Thank you Captain Obvious).

I think your best bet would be to either call someone who specifically builds roots style SC V8's, or try and get a technical book on SCing.

For the summer, I know this goes against hot-rodding, but maybe just put a regular intake and carb on so you can cruise around and enjoy whats left of summer...

Sorry I couldn't be more help