If your PCV valve is old, it could allow more oil to be sucked in as well.

In any case, a catch can is your best bet on a boosted car.

As for your piping, you need a lip on the intercooler and piping side for the coupler to grab on to.

Also doesn't hurt to double up on the number of clamps you use on both sides, and make sure the coupler and outside of the piping is free of any residue before you install it. Brake cleaner and a clean rag works.

That's what we had to do on a 24psi car anyways...