The hack is safe but Fairfight is a problem because it compares your statistics.
My legit account is banned as well by this "good" anticheat tool and with this account i never used any kind of hack.

I believe that it checks how directly you pick up items and watch to enemies and that stuff. This is my personal view so it can be false.

Currently (3 days) I use an account only with esp and no ban till yet. But this is no guarantee for you. There's always a risk if you use a hack. Hope I could help you.