Unfortunately I can't contest the first point, as it's one of the few major issues I have with the game... many of the characters seem pretty unconcerned with Foster asking lots of weird questions about what should be common information.
Although, Hobbins doesn't really strike me as being the sharpest knife in the drawer...
(I'll add that I also was pretty sure Hobbins would turn me in if I said the wrong thing...)
As for the latter point... the theft *isn't* a contrivance, honest.
These are very arbitrary stopping points I've made... most of the locations you can visit and revisit as needed. So while you technically can usually be klepto/obsessive and take/do everything as soon as you see it whether you currently need to or not, I do remember the game being pretty good at giving you reasons to do/take things at later points.
I didn't mind the fact that you have to distract Hobbins, either... he struck me as the type who prefers not to leave his workshop unless interrupted by guards or annoying inspectors.
Besides, why would he voluntarily leave to putter about in a room with junk and a broken robot anyway? (Or a room with a mysterious press and a walkway that leads nowhere?)
I'm not saying that simply having Hobbins wander the area on his own, leaving free time to snitch things, wouldn't have been a viable puzzle... maybe even a better one. I just don't have a problem with the current puzzle as it stands.
Peace & Luv, Liz