Why don't you just try it out and see Other than that, the 2 day ban proved that you can get banned again, other than that, there's no CHANCE of ban. It's not like you can say "Your chance of getting banned today is 12.3%"
I care more about the scalability on the methods rather than the GP/hr. 20k/h is enough if you can run 100 accounts on that method. 10 accounts on a F2P method is just not worth it and boring.
Just do it asap, F2P's far more watched by all jagex systems, there's hardly any bans on P2P by the automated system, while I have plenty of wipes on F2P