some explanations please? [BLACK PLAGUE SPOILERS]

[roketto]

first: what is up with that first hallucination philip has, where he is back on the boat and then he goes out into a very strange bunch of rooms, with hands and fire and all that? is that in his mind? what is the symbolism behind it?

second: who is clarence exactly? we are told he is a virus but why is he so human-ish for a virus?

third: WHY does philip tell his friend to kill all the tuurngait?! he seemed like he was a guy who was trying to just do the right thing all the time, why would he not want to blow up that horrible place and let it disappear along with the demons?

fourth: why exactly were the dogs and spiders and people "infected"? did the tuurngait just infect whatever was around? were the worms infected as well? i am especially confused about all of this because it seemed like the facility was testing on animals/people and then they became mutated. but apparently it was just the tuurngait possessing them? i don't really get it.

i am even more confused by the ending. the tuurngait say they want mercy from philip. what do they mean by that? is it because they want him to destroy the facility?

lots of questions here and i do have more but i'll wait for some answers to these ones first...