Thanks for pointing out the typos. I've edited those. To answer points 4-8...

4. There should probably be more options in the list, but I was trying to avoid letting them have access to classes that would require intensive study or training that the character might not actually have. For example, wizards study for years before being able to cast spells, but if the host spent his childhood learning to be a fighter or something instead, where did the dark half learn to cast spells? Of course, if the host trained to be a wizard, then the dark half could have been leaning over his shoulder so... I tried to give it options that would come from having innate gifts, but it would probably make more sense to just remove the restriction.

5 and 7. Hm... I had imagined the personality not in control at the time being unable to do anything but communicate with the other half, but it would be interesting if it could activate those abilities itself... although the Dark Half could potentially weaken the host by feeding an ability the host would soon need, or waste the use of the demonic body ability by using it prematurely.

6. Let me look at that after I've posted this; I may change it as suggested.

8. You know how when you're tired, you just forget to add some things... I'll go change that.

As for why I chose those demonic body options, they were just the first things that came to mind, but I may add more later.

Thanks for the advice, please keep it coming, especially on what the level adjustment should be.