The problem I have with this proposal is (if I understand it correctly) you want Karmashares LLC to back any Karma transaction involving paypal that doesn't work out...
in other words asking Karmashares to act as an insurer to guarantee transactions that do not involve Karmashares or its shareholders.
I don't see how that could be profitable unless they charge a hefty transaction fee pretty much the same way that credit card companies do.
I think in order to do this Karmashares would have to register as an MSB in 52 states (in the USA alone) which could cost millions of dollars.
if this is what your proposing then I have 3 problems with it.
1) it rewards the stupid... at the expense of the needy. money gets diverted away from "Doing good" projects to fund essentially transactions where people have not been acting responsibly and doing their own due diligence before transacting with each other.
2) it goes against the very core ethos of all crypto currencies.. and that is the user maintaining control and responsibility over their own money. The minute you introduce buyer and seller protections such as charge backs and escrow... you become no different from the Fiat system that already exists. Escrow is a good idea but it should not be controlled by a central authority (there are ways you can do this on the blockchain itself with multisig and time delayed transactions) but charge backs are just plain wrong. Why should a seller have to refund the money of the buyer claims he was ripped off without offering any proof? (this is how charge backs work atm)
3) Karmashares already has too many coins.. more than 10% of the entire supply. If they control too many (50%+ maybe even less than that) coins and all the coins get stolen then its game over for Karma. there are no second changes and no rising form the ashes.
the credit card system we have today was invented in the 1950s and it is broken.. please lets not replicate it....