Osage manipulates well with heat and it will not hurt the wood unless you over do it. I'd say to get the bow to floor tiller first at least and first brace would be better so you can line the string along with any other straightening.
How about some pics. You know, the only to break the FG mentality is cold turkey. Build a beautiful, well tillered bow and show them what a crooket stik can do.
You could reduce the width to 1 1/2" also. That would give you more thickness to work with.