Thai Chili Paste

Is this a good substitute for recipes that require peppers? Is there a rule of thumb re: how much paste = a pepper?

I think you’d be better off with dried, powdered cayenne or dried whole chilies. Fresh chilies will give you heat and a little flavor. The pastes usually have vinegar in them which gives them a different flavor than fresh. The dried chili flavor profile would be closer to a fresh chili.