on the old site i had a problem with a member who joined my RPs, and i do believe he was genuinely interested in the RP, but he was always arguing and disagreeing with me (the GM) what should i do if he starts doing this again here? he may not, and he may not even join my RPs but i would like to be able to do something so the RP is not ruined for the other players

GM's have almost complete Autonomy when it comes to their RP's, as long as they stay within the overall guild rules. You may prohibit someone from your RPs, you may make your own set of rules for within your RP (as long as they don't clash with the site's rules) etc. If you are going to ban someone from your RP I would suggest you do so with discretion and a little class. Don't make it rule #8 that so and so can't join (not fonz cool) but if they post in your RP, simply PM them and tell them they are not welcome and why. Easy and hopefully, drama free. Good luck.

Generally you have to just deal with it as GM. Of course if they get out of hand you can tell them to leave or tone it down, but I don't know if this person goes that far or not. If they don't stop or they keep posting even with them warned and/or dropped from the RP, then the mods are there to do something. The only way is not to accept them or if they argue anyway is to go to the mods. Remember you are the boss, the master and its your story, not theirs.

Well that is just me, maybe someone else will have something better to say. I am sure the mods will.

thanks guys