I had a set of 225-50/16 BFG g-Froce Sports on my 328iS. I pulled them the other day and saw that the rears were worn on the outside? Is this normal? I had an alignment done not long after I got the tires. I pulled the rears from my girlfriend's 328i and noticed that the rears where worn on the insides as expected.

I normally run 33-35PSI.

Uneven wear like that is normally caused by camber. If they are worn on the outside shoulder you could use a little more negative camber. Other than that you need to stop drifting the car.