P1250: replace the fuel pressure regulator. Just as I suspected in the other thread.
PO300b: Don't know. Doesn't even sound like a valid code.
P1397: camshaft position sensor "B" circuit. If you have a CPS on both intake & exhaust, I would guess it's the exhaust side that's bad.
P1188/89: Fuel control, bank 1 sensor 1 & bank 2 sensor 1. I believe these should go away after you replace the fuel pressure regulator. If not, then you should move on to replace the O2 sensors.
My thoughts, which is in no way professional, but based on my previous experience of a similar nature: Your primary problem is the fuel pressure regulator. The diaphragm in it that holds back the fuel pressure has probably ruptured, causing the flooding of gas on your spark plugs and the cylinders. The other stuff happened as a result of that. If you continue running the car, you could be close to damaging the catalytic converter, if it hasn't been damaged already.