Not all payment gateways provide mass or split payment. We only support what is common between payment gateways.
CMGroupBuying doesn't not provide any point system. We have integrate with AlphaUserPoint and JomSocial, if you want to use these point systems, you need to have in your mind what points are for, how your users receive point, how they use their points, etc... Eg, you want to allow your users exchange 1 point for 1 US dollar, or let them buy 10 points with 5 dollars... so you need to setup those features in your point system, not in CMGroupBuying.
Regards,
Hung