Just a couple plot questions... [spoilers]

[Kedjane]

Starting with the more obvious one if I remember it right Howard didn't kill himself. He went into the "Tuurngait dreamland" that you go into right before the end, but either the Tuurngaits mind was so powerful that he died from communicating with it or he failed the tests and died.
Why Philip tells us to kill the Tuurngait is a bit trickier, but I believe it's because of simple human anger. He's angry at the Tuurngait for killing his father. Either that or it has something to do with "not making the same mistake twice", not letting the Tuurngait live like his father did. I can't remember exactly, but I believe it has been discussed before and it had something to do with the texts he writes to the player/whoever recieves.