You've already done a lot of work, and if you enjoy it, keep going. But to answer your questions from the first post:
I'm a bit of a purist. I like the wilderness areas with less POIs. It makes them actually feel like wilderness.
Between stumps, camps, cabins, and zombies...loot doesn't feel that bad. You get what you need without skyrocketting progression.
Finally, just my own taste here, the prefabs with the already built walls just seems a bit cheesy. Are you at least adding sleeper spawns to them?