Powerbot is safe. It's not like Epicbot with all these malicious things going around.
What do you plan on botting?
Because every bot has his own ban-rate.
I botted 99 firemaking 20 hours a day in my holidays, no ban.
But when I wanted to achieve 99 magic, I got banned on the 2nd hour botting Gatestones in a Dungeon, which resulted in a 2 week ban and a roll-back.
I hope I answered your questions.