Hey Aaron,
In the old days all you did was write the bpm on a sticker on the cover and that was it :-).
I personally wouldn’t want to keep cards (albeit the idea in itself could probably work). The thing is that in a -usually- fairly crowded DJ booth it’s hard to keep that kind of thing organised (when I still play CD’s I sometimes already have problems where to leave the sleeves lol).
There are some options to export stuff from Traktor (read on the blog and forum about those).
Personally I use MixVibes Cross which has an automatic sync to RekordBox. So when I go out, I can just select the playlists I want to take with me, move them to my USB-stick and be off.
I hate doing double work, unfortunately it’s still impossible to play on every platfrom without doing some doubles.
Greetinx.