I must admit, this is the first time I've seen your project. I started something similar once, but I have trouble sticking to multi-generational challenges/projects. I cleared Sunset Valley, and the idea was to buy each lot with my sim, and then build it until ready to add the rabbit hole, at which point it is 'sold on my sim's behalf'. That way, I could have one sim be founder of the town, and any new sims added are randomly generated sims (plus the homeless townies that start in each town) plus the future generations of my founder. I wanted my sim/s to be able to build (in the architect career) all the houses of all the sims. Seeing what you've got here makes me feel like having another go at it! Only this time, I think I'll use an empty world that I would have created in CAW so I can have the lots the exact size I want. I've made an island of 15x15s, this time I think I'll make something more varied. Once I fiddle with the files to make it work again after the latest patch.
Kudos to you for sticking with it!! It's a big job, and you're doing really well!