I feel that every single program always has a chance of it being unsafe.
If you look at this thread, 2nd post: (you need an account to see links)
You'll see the guidelines behind whether the script/program is "safe".
I guess with it being unsupported, there could be bugs, be unsafe or have issues along the way but from what I saw, it runs the same as you would be if you were playing it yourself. There's nothing weird about it, it clicks every single thing you would.
It would only be unsafe if you ran if 24/7. Run it the same way you would if you "played it yourself" and you should be fine.
But of course, that's just my opinion. Good luck ^^