After reading your post I would say heat the ones on the rollbar with the plumbing torch. On the hood you'll probably have to drill them and use an ez-out to back them out. If you don't have any experience using ez-outs, beware. They are very very hardened and brittle. You absolutely do not want to side load them because if you break it off in the hole you are pretty much screwed. Is that any help?
PB Blaster is overrated, IMHO. Use a 50/50 mix of ATF and Acetone. Much better and loosening stuck bolts.