1) Sure. Raf'll probably be able to figure out they're illusions if they're over an extended time, though he might think his own mind's creating them. It's a little complicated, because he's got a computer chip in his brain but for the most part that just gives him accelerated reflexes and a computer program of a fox that mostly just appears to him.

2) Sure, and in that case he's also welcome to see the fox if the fox has anything to say. I play it as being visible on the second level generally, so I assume this would be similar.

3) Poison might not work, magic sealing should.