Easier way to mark unused cards as trade-able

I have a large collection, and I love trading any cards that aren't currently in a deck.  It'd be nice if there was some hook to mark anything unused as trade-able.  I thought of a few options:
- a function to mark all cards not in decks as tradeable.  This includes cases where I have 4 copies and only one is in a deck.  This gets complicated if there are multiple entries for a card.
- provide a deck count column in the inventory export.  This would allow me to export, tweak in Excel to use formulas to update the tradelist count, clear my inventory, and then import the new .csv file.  I don't mind doing this work, but there's no options for deck count int he export.

Some more manual options (but possibly easier for the developers) are:
- filter/sort collection based on number of cards in trade list.   This would let me look for cards that aren't in the trade list to add them easily. 
- filter/sort by number of cards in decks.  This lets me find all cards not in decks so I can mark them as tradeable.

Thanks for an awesome site!