On the oil question I have three thoughts.
1) Any chance that someone has overfilled this drive a bit? It happens all time. I would drain it and refill it to exactly what the book says (I can get this amount if you don't have it. I will need the serial number of the drive though to make sure I give you the correct amount. They change a little between model years).
2) If you have a tiny leak around the shaft seals you sometimes can get water into gear which will act like you have over filled the gear. So I would drain the drive and see if you get more out than you should and examine the fluid to see if it looks milky at all. And while you are at it rub the fluid between your fingers to see if you feel any grit (metal). It doesn't take much water, at the higher RPM, to pressurize the overfilled engine so
the oil pushes up.
3) Does the fluid get really hot when this happens? If so it could be you have a bearing that is overheating. This is pretty rare, but it can make the fluid so hot that it sort of bubbles.
Hope this helps.