How can it be made faster?  lower difficulty+lower blockreward to get confirmations faster? 

In it's current state, it can't be used for something quick like a checkout line in a store.

same.  and the market for buying/selling computer hardware seems pretty good

mining is best when you do it on one or two cards that you already have for gaming

agreed, earn your coins!

I run one hd5970 in the primary x16 slot and one hd7970 in an x4 slot.

The display is attached to the 7970, no image during post, have to attach a monitor to the 5970 to do pre-boot stuff.  Once the drivers load, display comes up.

I have the display on the 7970 because it is a better card for gaming.

As for mining, it works well, but only with older drivers.  12.5b and 12.6b did not play nice with the 5970 (no display attached=idle gpu, trying to sleep or something), so go and use 12.4 drivers.