Thought it might be quite useful to be able to select multiple cards in inventory/wishlist/tradelist and be able to set all selections at once. Obviously this wouldn't really work too well for edition, depending on what you had selected... but, Langage and Condition should apply to everything, regardless of selection without any issues.

I had thought to go through my wishlist to set all languages to English, but so many individual clicks would be involved that I give up. :P

I concur. I came back to update my decklist only to find that now there are more categories I can fill in, but I have to do them individually for each card. An option to edit them all or several at once would help a ton.