I think dealing with karma by status [reg, vip, etc] is a bad idea, though it does bring to light a real issue.  Lately, we've been forced to deal with a LOT of RDMing, RDMers on the server - many are new, and learn not to do it, manyfold more are not so mature.
I was wondering if it is possible to hard code something to deal with this - something that kicks users who MASS RDM beyond what leniency that may already exist / be reasonably necessary.
I mean, my thought would be that such an idea would work like this:
Have a variable for each user - lets call it penaltyPoints.
When a player shoots another player, and either injures or kills that player, the teams of the two involved in the combat are compared - and either penaltyPoints is incremented, or not.  
| TRAITORS: 
 | 
| Traitor kills / injures Innocent or Detective: 
 | No increment of pentaltyPoints 
 | 
| Traitor injures another Traitor: 
 | Small increment of penaltyPoints 
 | 
| Traitor kills another Traitor: 
 | Large increment of penaltyPoints 
 | 
| INNOCENTS AND DETECTIVES 
 | 
| Innocent or Detective  hurts or kills a Traitor: 
 | No increment of penaltyPoints 
 | 
| Innocent or Detective hurts a Innocent or Detective: 
 | Small increment of penaltyPoints 
 | 
| Innocent kills another Innocent: 
 | Large increment of penaltyPoints 
 | 
| Detective kills an Innocent: 
 | Large increment of penaltyPoints 
 | 
| Detective kills another Detective: 
 | Large increment of penaltyPoints 
 | 
| Innocent kills a Detective: 
 | Huge increment of penaltyPoints 
 | 
Have a set threshold, when a user's penaltyPoints is equal or greater to that, kick the user.  At various penaltyPoint values, have a means of warning the user about how close to being kicked he / she is.
I know, what about accidents?  IMO, if there was some way to keep track of it, I'd say make it so it was only possible to increment playerPoints [AND by that extension, affect the karma] when it comes to explosives at least by keeping tack of the damage only from when the flame entities are created, etc, to a second or two after.  The idea behind that is to reduce the chance of somebody getting karma fucked - or in the case of this system, penaltyPoint screwed - by team mates stupidly walking into fires created by explosives set off by their own team mates.
And YES, I know it feels complicated - the penaltyPoints system thing, but usually programming projects that seem straight foreward can be rather complicated - especially if you want to severely reduce the number of exploitable loopholes.
This is just an idea I had though, an interesting albiet imperfect means of dealing with, kicking problem mass RDMers without worrying about the absence or prsence of VIPs, or Admins.