farthest offset i can go

^^ By using a more negative offset without either upgrading the suspension components (better coils) or by installing wider control arms (titan swap) you increase your scrub radius which, like toryroyce said acts like a lever on your wheels bearings and hub. Now unless you drive your truck incredibly hard around corners and jump it like a wild a$$ indian I doubt you'll have any problems.

The more negative the offset the more the wheel looks the more the mounting point to the hub is pushed in, the more "deep dished" the wheel looks. Going from +30mm to 0mm will have this effect.

Yes

Plenty of members on this forum, and even other guys who own trucks put on wheels with more negative offset and even negative offset and have zero wheel bearing or hub issues. Of course it can cause more strain on parts, its almost never enough to cause major issues. The only foreseeable problem is the further the tires stick out, the more sh!t gets flung at the sides of your truck. I'm not sure how you use your truck but that will affect it.