Of the former, I ask this: Why would Sisyphus keep pushing the damn stone up the hill? He knows it's just going to roll back down as soon as he reaches the top. And he was already in the Underworld so what could they do, kill him? Sure, they could pull a "Prometheus Special" on him, and have vultures rip out his intestines every day, but at least then the horrible pain he's feeling is being caused by someone else. It seems like it would beat the spine-cracking agony you subject yourself to by pushing a boulder up a hill all day, every day.
Or maybe I'm underestimating Hades' punishment capabilities. He might be taking lessons from Garth Ennis in "Creative Pain Disbursement", at which point I'd say, go with the rock.
The things that occur to you when looking at a poster detailing what won the 1997 Nobel Prize Award for Physics.
As to the latter, I remember my freak out over Seward Trainer being name-dropped as the fellow Aunt May was staying out all night with in Ultimate Spider-Man. You might remember it, I was pleading with Bendis not to go there, "there" being the Clone Saga. Obviously he ignored that, but so far no Seward Trainer.
I'm beginning to think Bendis name dropped Dr. Trainer just to send those of us familiar with the Clone Saga into a panic. It dredges up all kinds of unpleasant memories: The lady Dr. Octopus, Ben Reilly in that stupid Spider-Man outfit (which as someone said, works much better on Spider-Girl. Why it does, I can't figure), Peter without powers trying to snoop around on Trainer, and so on.
But up to this point, he doesn't appear to be a factor. That would play into what BMB appears to be trying: take out all the extraneous crap the original '90s Clone Saga gathered over the two years it was going on, and just stick to a simple story about lots and lots of Peter Parkers, if such a thing can be simple.
As for how well it all winds up working, well, the jury is still out, with a couple of issues to go. The reappearance of his supposedly dead father does not bode well.