It's really nice to have new downtime activities, and the four you propose are good. Here's some feeback:
- I don't like the d10 events on the gardening project every time you do it. Extremes might happen where you never get an event or you get one every time, which might be really tiresome
- On revelry: I think players should be able to use other characteristics than Presence (Intuition and Reason at least). Using wealth as a bonus is super smart. Gaining a free follower seems really really strong. The title is super cool!
All in all it's a pretty solid entry, with some cool events and benefits that really convey the theme of each activity.