Can someone help me understand the rep/karma system please? All factions/towns will have separate rep meters correct? So I can have good rep with some and bad with others but the karma is just one separate stat that is the average pretty much of ALL your rep with everyone? So I could be generally good and have more good rep than bad so my karma will be more on the good side? What does karma affect than if rep is separate with everyone? I'm confused...
You're right about each faction (this includes towns and such) having their own Reputation meter with you. You can he loved some places and loathed in others. Karma doesn't really come into it at all.
Karma is something completely seperate and more of the game's way of saying what you're like. So, you'll gain karma by giving water to beggars, etc, but I don't think, say, joining the Ceasar's Legion will lower your karma.
Really, I think Karma will hardly play a part in NV -- Reputation is the real thing, and Karma's probably just there as it's Fallout tradition.