Working hard and being in shape neither proves or disproves steroid use.
Even on gear you still have to put the work in, they just accelerate what you get out of your training, the only reason they're outlawed is because of how dangerous they are.

As for your question 'do you think the boxing orginisations would allow pac to fight with steroids'... no, but they have to catch him first... and it wouldn't be the first time in boxing or profesional sports where they've managed to keep it under the radar.

IMO almost every pro-athlete is getting some form of helping hand, the trick is how much you can get away with.