i like some evil ncps (edwin, viconia, sharteel) but i like playing good so how do i stop them from complaining when my rep goes up?

You turn off their voices in game properties. :D
No other way really.

could a leader with high charisma do it?

Nope... the rep score is all that effects them. The lower the rep, the happier evil NPCs are. Vice versa for good ones.
Neutral want to be somewhere in the middle.

I like a lot of the evil NPCs too so to keep them from complaining I get caught stealing. Have your theif go into a building alone and break into a chest when the guards bust in tell them you'll tear them from limb to limb and then head for the door. You'll only loose one rep point, so if you keep yourself in the 12 range, they'll deal with it.

Personally, I like to round up all the evil characters and then take them for a good old paladin hunt. Then we are all happy. Except of course the paladins. hehehe...

Hey! Look it's the Paladin hater!!!!!!!

HOO HA!

K... Whats so bad about Paladins? :D

they are smelling so smarmy :)

Is it just me or are all the evil ncps better then the good ones? :confused:

For me, the evil ones worked much better than the good. That may have something to do with the way I play though. After all, minsc gets a little pissed when I gut a paladin for looking at me the wrong way. :D

It's just you. I always play good and all good NPCs rock as well. ;)