Changeling said:No. Cuz Thors Norse myth, and Hercules is Greek mythology.
Definitely not for the first movie. A crossover with the Greek gods could be a really cool idea for a Thor sequel, though. Rather than making Herc appear as just a random buddy of Thor's, have Thor and the Asgardians encounter Olympus and make it the basis for the whole movie. That could work.
Naturally. Thor and Herc fight almost every time they see each other, even though they're buddies.
Personally, I'd go for a Hela/Pluto team-up, myself. Or maybe Ulik or the Executioner and Enchantress/Ares. Loki's gonna be the main villain for the first film, so it'd be nice to change it up for the sequels rather than having Loki, Loki, Loki all the time.