One of my molly's has been hanging out at the top of the tank blowing bubbles like my bettas do. Is this a normal behavior? It seems odd to me.

Add airstone, salt and feed peas might be bloat

I used frozen peas and took the pea out of the casing. My fish liked it.

I have many Molly's and occasionally they do the same thing. From observing them,(without making them feel self-conscious,lol) it's not a regular behavior. However, I have several Platty's in the same tank and they do the same thing. They may just be copying each other's behavior. I'll do some research and get back to you. Hope that helps.