Regarding pressure drop, it could well be the aerated oil causing the pressure drop, fluid can't be compressed but, air can so, you could loose oil pressure with aerated oil and air doesn't lubricate very well, either.
My own little story on my pictured car. I had to pull the engine to replace a clutch and when I put it back in, there must have been a piece of something in the AN flare, on the intake side of the pump. I noticed a small drop in oil pressure, maybe 5lb (80 psi was normal). After 2 practice sessions, it had dropped more, maybe 12-15 total. I went all through the fittings and when I tighten one of them (a union) the pressure went up a little but, not to the full 80. With the external pressure adjustment I raised it to about 70+. I thought to myself, that will be ok. About 10 minutes in the race the engine, a rod bearing seized and put a hole in the block, about 10" behind me. Lesson learned!
Air and oil don't mix, so to speak! One compresses and one don't.