One temporary suggestion for seriously improving the card picker that pops up when you pick cards for quests, jewels or money in the bazaar is to add cross-filter buttons for rarity to the screen. Similar to the arrow buttons you've allready put in for scrolling.

Right now it takes sorting through a ton of junk if all you can afford is commons (you have 1 amulet) or uncommons (you have 2). More importantly, if you have an option to only pick one card what you're looking for is probably a rare. If you have an option to trade jewels for many cards, you're probably looking for commons. And since there's a ton of stuff in there you might not have a clue what you're looking for and just want to browse a category.

A button to filter out multicolored would also be quite welcome.