By all means reduce the oil level in the tranny to the correct level--HOT. You might consider changing it since it has been severely stressed with air entrainment and probable overheating.

The vacuum lines to the transmission will not injest oil unless the seal in the transmission device is ruptured. There are two--one is the shift modulator (left side of tranny) and the other is the upshift delay device on the right (passenger) side. The upshift delay vacuum is only activated on a cold start and then for a couple of minutes. It holds the tranny in 2nd to a higher RPM for faster catalyst warm-up.

Easy to test--simply remove the hose at the tranny end and see what comes out. Should be clean--no oil. If ANY oil present, that device is faulty.