The chain pet stores take.....not great......care of their Bettas and that definitely takes a toll on their lifespan. The fins spitting, as long as they aren't getting worse, might be another sign of old age. Just a couple days ago I had a rescue Betta that wouldn't eat flakes or pellets, not even bloodworms. I tried frozen thawed adult brine shrimp, and he ate it right away! Don't feed it every day to them as they are only a treat (it would be like eating 3 donuts everyday) but they have a lot of protein in them and Betta fish love them. You can get them at any pet store, they are only around 5 bucks.