I'm sure even selfless, noble Will has his rare days that he would rather be dead than doomed to do this forever

Perhaps so. Because he would be, if it hadn't been for Jack. No kid, no one day. I see Will as something more than human, now, is the thing, and such pettiness would be beneath him. But of course he can be written as the trapped and unhappy man, too. He certainly has a fascinating character arc through these movies, and there are all kinds of directions on can go, post-AWE.

A very thought-provoking piece you've done here!