You may well find that the native code doesn't perform much better. I have taken a run at the fence with native code on Android for a different app - I wasn't any happier with the native version and it was harder to write.
I haven't quite figured out the store thing apart from Google and Amazon. OTOH, you can just stick a link to an apk file on a web page and people can install that way. Our app is free (for now) so we aren't too worried about it. I think we will just do Google Play and Amazon and a link on our website - at least at first.
I belong to the mobile apps group on linked in and a recent poll asked people which platform they preferred and the overwhelming response was iOS because those people are fine with spending money where the Android crowd is a bunch of cheap bastards that just pirate your stuff anyhow.
Also - the level of malware on Anrdoid is pretty high.