The day blizzard bans g15s is the day we can start worrying about the likes of autohotkey being used and causing problems.

If your not using it to automate, its not an issue, the same way if you arent making automacros on your keyboard, its fine. As for the " can they differentiate between ahk and a bot program" as the ahk users on this forum arent being banned for botting, and bots are, I think that is pretty self explanitory.