I really love this concept and the way you've laid it out. I play much more AD&D and OSE than BitD, and I'm adapting this idea to the way I run downtime in those systems. Thanks so much for sharing.
Hey thanks for the praise!
If you're looking for a more fantasy and OSR-y take on this and have the $ to spend, you should also check out Trophy Hearthfire, either in the Codex - Hearthfire issue or the Hearthfire section of Trophy Gold (assuming you haven't already). Basically you a list of downtime actions in your fantasy town, and every time you take one of them, you answer another question from its list. So when you go Carousing the first time, you describe your favorite tavern in town. The second time, you describe your favorite meal there (and other people tell you why your choice is bad, actually). When you put money in your Hoard, you narrate flashbacks about what's motivating you to get money by adventuring. etc.
Though of course, whatever you're doing yourself is probably more interesting and exciting for your table. :)