In Deus Ex, what will normally incapacitate a mook will kill JC, at first I thought it was because they are lazy but I then realized that the UNATCO made it so that if he is incapcitated he activates a psuedo killswitch which will have himself self terminate if he is involuntarily incapacitated.
I always thought of it as seeing that if you pass out in enemy territory, it is just shorthand for saying that the enemies would have finished you off when you were out. Although the puddle of blood under you would support your theory...
Also, the tear gas mentions about causing bronchitis, since the nano augs process certain things quicker. This also means it can directly affect JC and prolonged exposure can lead to death.
In Deus Ex, you always open to a particular section of a book, even when it's closed, and typically to the pages most pressing to current events, or the ones that are most contemplatitively philosophical. For example, behind the Clerk's desk in the 'Ton Hotel, there is a copy of G.K. Chesterton's The Man Who Was Thursday, and you open to a discussion of political and philosophical anarchy. You might think "Well why do we open to that page instead of any particular other?" and then you think Of course that's what JC Denton would open to!
In the beginning, Paul will scold you if you choose to mainly fight your way through Liberty Island, which makes sense as he's a firm believer in Thou Shall Not Kill. It later makes even more sense because you realize those were his men you killed.