Other than piston rings and a leak between the intake mani and heads allowing boost into the lifter valley, how can boost get into my lower end?

 

If you mean pressurized blowby gasses... our engine creates a lot of them, even brand new. It's just part of the design.
With the turbo, I think it makes things worse, due to higher cyl pressures... But it's nothing to worry about, usually.

 

Thats about it, unless your CDR is post turbo.

 

if you lug it most of the time and don't change the oil, it can build up carbon in the ring groves, and develop blow buy.

 

DAMNIT! I knew that was why I was leaking oil all over!!!