Blue ash bark is totally different from white ash and is easy to spot. It generally grows along streams and can have a smooth bark with corky bits on it at the base. The oppisite branching pattern and leaves are trhe same as white ash- that's the only way I'd know it's an ash, because I generally first notice the bark in identifying white ash.
I think ash is "OK" as a bow wood. My first ash bow snapped (I had not a clue how to make a bow then) and my recent one was hard to tiller and took some set despite low draw weight for length (45#, 68" nock to nock). It shoots very smoothly though, but lacks the cast of a black locust bow I built at the same time, which has a similar draw weight, is 66" nock to nock, and took less set.