It's pretty much about 3% now, which is a pretty low guess. The tools have been updated and everything is double checked so the risk is pretty damn low. I suggest you use Plialects guide: https://github.com/Plailect/Guide/wiki
As it is the best right now. Don't worry about your O3DS. The biggest risk here is downgrading to 2.1 and the o3ds can run this natively (the n3ds can not) so no worries there.
O that's good to hear. I'm currently on 4.4 with a Gateway and it works alright but it lacks support for a few things I would like.
however it does support the spider exploit for scanning QR codes (just have to install browser cia with BBM) and it has it own cheat system and some other nice things. Mostly I use the spider exploit, will this still work? Other then that I haven't really figured out how to play back up games with this except for installing .cia files. With Gateway i just put .3ds games on my microSD and go. Is this still possible with this hack or is there some other trick to it? Sorry for being such a noob