They hated Gold for greedily overcharging their rent and controlling basically everyone’s buildings or businesses. I think they knew they’d either be out on the streets or he might arrange “accidental fires” if they didn’t pay up. Without knowing his fairy tale identity, they still feared him more than Regina.
When they find out he’s Rumpelstiltskin, what Charming called “the most dangerous man in the realms” and a “scourge” on the kingdoms (keep in mind the sword fight in the infinite forest with Rumpel being a fan of true love, precedes the wedding, and Charming personally helping arrange for the guy to be locked up), they should probably hate him even more.
I could see Belle being a go-between but I don’t think that would do her any favors or help her to fit in. The more I think about her doing that the more I think of her as a Sidney Glass. He was madly in love Regina, would do anything for her and at times did try to tell people that she wasn’t that bad. The guy didn’t seem to have many friends. They just tolerated him to keep off Regina’s bad side and otherwise felt sorry for him. Once Emma finally knew how bad Regina was, Sidney Glass’s love for her downright disgusted Emma.
If people know she’s aligned with Rumpel, I see Belle with a lot more pity than friendship.