I haven't really had any problems with bellies. They supposedly aren't the best for tooling or heavy strap goods, but I wouldn't worry about making anything else out of them.
As long as you aren't putting a lot of stress on the fibers they should be fine. Knife sheaths, bags, tool pockets, bracelets, wallets, any kind of covers should be good as well.
Now, that being said, I wouldn't sell an expensive tooled molded pancake holster out of the stuff. Guns are heavy.
Just keep in mind that bellies aren't the toughest part of the hide. And just because it's a belly doesn't mean it's junk.
Have fun.