Will you be able to build mixed purpose buildings?
Idea here is that you can live above your shop or something on a commercial lot, but you wouldn't be able to have a shop on a residential lot just because you also live there. Basically, I plan on enforcing lots like this:
Residential lots: Houses, hobo boxes, inconspicuous below-ground secret bases, and, provided that there won't be a 'general' lot category, anything that doesn't fit into the lots below, such as parks, boat docks, garages, etc.
Industrial lots: Only for industrial builds. These lots can have factory shops on them provided that they're using crafting events and not sale events.
Commercial lots: Shops that use sale events can only be made on these lots, but provided that it has a shop, you can also live there. Commercial lots would also encompass restaurants, various services (such as lawyers, taxi companies, etc.), and probably gas stations if Diggy uses the gas mod, but I might let gas stations pass on industrial lots, also.
And obviously Admin lots are for whatever the forget we need them for.
Not sure if Diggy added any extra specializations, but going beyond 3 or 4 player-accessible types is a tad excessive.