It's really a pain to add a card, then have to edit card details to add an Edition.

I understand the need for this if the card is in more than one Edition. However, there are a lot of cards that are only in one. It would be nice if the Edition field automatically set itself when you add the card if there's only one possible Edition anyway.

Also in the spirit of making card details easier to manage, I'd like a way to optionally set a default for "condition" and "language." All but one of my cards are English, but it's not feasible to go edit the details on them all...

I agree with this problem... I spend a lot of time editing the sets and condition of my cards.

A default would be nice... perhaps the most recent set? + English language and Mint condition? Though I suspect people will want their default language being... their language in some cases!