Ash is a great wood. I agree with all the other guys, you don't want to use dead standing wood for bows. You could try it for arrows, but if it was me, I'd be hewing out some big fruit bowls.
As for splitting logs, ash is about as good as it comes. A large log might be hard to start, but once you get the wedges in it practically splits itself.
It's also very easy to dry without degrade, unlike most other bow woods. Just seal the end grain, take the bark off, no need to seal the back.