As much as I would like to see a trade feature I can't see it happening. It would be WAY to easy to abuse.
I also like not getting a card every other game the difficulty to get the cards make it more challenging.
The only thing that bothers me is the amount of useless cards I have. I have a handfull of items i can't even use, but that is easily fixable on my part.
 "ACTION TURNIP!!!"){kind=icon}
 "Perfect Balance"){kind=icon}
 "Kongai"){kind=icon}