Would it be possible to add "Graded" to condition, then another drop down for PSA, BGS, etc. + the grade?

Would be amazing if I could search for graded Magic cards.

Thank you for your time. This site is awesome.

As a new owner of a gem mint graded card, there is no way to flag a card as graded. Think that will ever come to be an option?

It's on my todo list. You can use the tags feature for this in the mean time, although they are only visible to you and not your trade partners. I did think to introduce "public" inventory tags for purposes like these, but didn't get to it yet :)