Alas Randall, as I understand, there is no easy way to do this

the methods you have stated through keywords in the manage store section are it to my knowledge, and yes when you get close to a thousand cards it becomes an insurmountable problem.
It is something I have tried to address recently with clickable links in my store but it's less than perfect.
I would love to hear if others have any ideas
I do recall reading a while back (from Mindy I think) that the majority of card purchases are through the general categories and searches and that very few sales are from folks browsing our stores. Nonetheless, I do promote MY store to people and like to think they can get around without too much frustration and find what they need. It is in a way representing me.
I put in time on it when I can but on the whole it seems very limited in what you can achieve,
Will check back to see what other ideas come from this.
Pamela