Rp fighting is really not to my taste at all.
I agree with bilbous I would not stop it from happening. From what i have seen it is almost always likely to end just as it did when we were 8 years old doing this with army men or barbies (insert whatever toys you used regardless of gender) "I shot you . . ." "no, you did not I have armor on" Substituting RP battles for Deuling is useful for those who agree to the rp battle if they cannot stand the dueling system is acceptable, but certainly not my ideal. I hope we can make some improvements on battle system. In the mean time realize that rp battling in the common area would be just as OOC as PVP dueling at harnquists. Arrange your RP battles for somewhere quiet where you will not be disturbed by "PLers." According to what you said above the person came into challenging you through RP, i see no problem with that.
In DnD you rp battle to an extent, but you have stats and dice and such to stop absurd bragodocious feats from being possible, their game balance has had 30 years or so to work itself out. Be patient and we may well have some improvements. If you legitimately enjoy RP fighting (again i cannot understand why you would), then just take care to do so in a place that is more in character. If people are bugging you move. I recall some good rp battles between Zakk and farren Kutter IMO this was only possible because the same player controlled bot combatants and could script the outcome to suit his story needs. It worked as a piece of writing more than an in game interaction and justified some elements of Farren's characters.
One thing i know for certain, the quality of Role-playing in planeshift is in no way linked to the success or failure of Rp fighting. I never needed to rp battle and was lauded as a "good rper" I hosted player events and i dueled people in the tournaments. I slew noobs who challenged me as well. The duel/combat needs work, but if it was removed and replaced with:
* Xillix Queen of Fools takes sword and swings wide, the light of the azure sun blinding you as the strike heads for your throat
other combatant: "I close my eyes and focus on the training sinto gave me and parry though blinded"
I think I would cry.
Good luck on your rp fighting, try to do it in a place you will not be disturbed or use one of the other chat tabs for it.