To cut a long story short (during which I realized I was now literally doing the same thing at home that I do at work, setting up a web application against Postgresql), I now have a Pretend You're Xyzzy server running locally which I'm free to customize to the best of my ability. Cards and decks are just stored in a plain understandable layout in the database, and I've entered a few testing ones that you can see here - and ravenworks and I discovered that if you start a game with too few white cards it'll go into a panic and continually try to shuffle them eternally until you terminate the server.

Therefore, feel free to go mad making up questions and potential answers if you'd like to do a Hatoful special! I think most of us found that we liked the two or three-slot ones the most, but a good mix would be great.