I wouldnt see where this would cause conflicts, just tack it onto his points system
I havent messed with his stuff, so I dont know how easily it would be to convert something you have specially from that
edit: yeah, inferno is still a paid hack. i have memories of a site which used it, and it wasnt that great, although it was a year ago. Therefor chances of conversion are relatively slim unless i have access to at least his database schema. I still have faith in the ability to link up the points though, and thus no compatibility conflicts
edit: oh and yeah, the admin can, right now, add cards to the set through the admin cp. all thats needed are the blue and red images, properly sized. the system will take care of storing the card, renaming it, and setting it up for immediate consumption by the forums :-p (i tested it of course)