As sort of an aside, I think alot of people are wrong on the ECL of the half-ogre. I think ECL one is appropriate, considering that yes you do more damage on average than a human of one higher level, but you also sacrifice one hit die and you're a half-ogre! If you dont choose a combat focused class you're going to be pretty well below average, and even if you do you'll be a total social outcast. I think at an ECL 1 half-ogres are defenitely balanced, and I think as has been said before, it's really up to the DM to decide what he thinks is appropriate for his game. Some DM's may want to allow everything in, and just adjust encounters to factor in PC's increased power, others may want very low-power games with no PrC's and such, but since the options are out there it's all up to you. There's no reason to build in artificial restrictions, those sorts of things are up to the individual group.