I've been on a kick about simple rulesets lately too. I like what you have framed out here, and I
really like your kharma chit idea. It's a real nice link between RP influencing game outcome. keep us updated!
I'd also recommend looking at the new Savage Worlds ruleset. My gaming group is gearing up for a Necessary Evil campaign as we speak. It appears like it will be pleasingly simple...we'll see. To portray skill-ups, you increase the die thrown as X skill level increases. You go from d4>d6>d8>etc. to beat a set value to pass the test. Nice, simple, & no tables to look up.
Another thought....last year I whipped up some real simple old west skirmish rules (I actually whipped them up to be extremely simple, because I wanted to introduce my pre-teen kids to tabletop gaming). The rolls are typically just d6 roll off between opponents. Higher wins and the results are drawn from
custom made card decks. The odds of a shot being a kill are thereby governed by the dice-off and the odds of pulling a kill shot from the deck. I made up a few different decks: shoot deck, fight (melee) deck, duel deck, and also a deck of each character to determine play order. Here's a sample of some of the 'shoot' deck cards:
