I think the problem is that we don't have the code for the Avatar, and simply calling the function would include the cost-reducing effect. But what do i know?
I'll do the white cards first. I guess they shouldn't be too hard once i find out why
Vengeful Archon prevents the damage just fine but doesn't shoot back. Also, while i believe you that the white Leyline is impossible, i'll still try

Harder cards (just by looking at the list, may be easy though):
Mass PolymorphNecrotic PlaguePhylactery LichReassembling Skeleton (Yeah, it probably wasn't a good idea to try this as my 3rd card ever

I still have no idea how to take control of the rules engine card to activate abilities out of a graveyard (triggers work fine))
Wild EvocationObstinate Baloth (you already completed it, right?)
I guess thats it.
I still have a question about the distribution. To get it into your (jatill's) release, should i send you the .exe/.csv/.dat or the .c files or both? What else do you need to put it into My2000?
*Edit: Just checked, i'm working on the following cards in white.
Celestial PurgeInfantry VeteranInspired ChargeLeyline of Sanctity (?)
Palace GuardRoc EggSilenceVengeful Archon