How much oil is "OK" to have on the compressor section?
My motor does consume a little oil, but this is normal for forged (relatively new) motors.
No indications of blowing smoke or fouling plugs, but this is what I've got in the compressor:

 

4AN line (filtered) - no restrictor.
20-30psi at idle. 70psi peak. (measured at the turbo)

 

Could probably use a restrictor, those seals will flex at 70psi.

Is that the stock 300zx turbo? If so you could probably look up the spec at the turbo.

 

some of those nissan t3 60 trim still have the obsolete static seal. that's a common cause of compressor leakage. it can be upgraded to dynamic seal by replacing the thrust system and the backplate.
Otherwise, yes, 70psi of oil is too much. Turbo is happy with 20-30 psi max.
You should try the 1/16" restrictor first as well as some good 5-50 oil. Also, make sure your air filter is not too restrictive. otherwise, the resulting vacuum could make your compressor suck the oil out of the center section even if the seals are good.

 

Blaast that's your compressor cover on it.. It's a generic .60/.63 T3 - don't know seal config as I've never disassembled it.
Big cone air filter.
I'll try a restrictor. I have it off as my manifold is being re-worked.