I think there's a tendency to go a little crazy on your first bow when you start learning about techniques as you go along. (I know I did) You start making a perfectly reasonable flat bow and then you're like, "Ooh, heat treating, I should do that; wow, recurves look good, I want some of them; sinew? why not?; R/D/R/D, that's what I need...etc" It's as if you think you might never make another bow again and you want everything on this one, or that all these are performance enhancing techniques with no trade offs or drawbacks that can be slapped on any bow to improve them. I'm not accusing you of this, it just struck me that this was a tendency. I think you're wise to heed Darsoul's advice and keep it simple at first. A long, straight, untreated flatbow is a fine and dangerous weapon that doesn't need anything to improve it.