I don't see a problem with multi-use zoning or living above your store, no. My town has an immigrant family that's running a "department store" of various kinds of secondhand junk out of their barn, and they're not the problem here. They've got everything from used clothing to tractor parts, and I'd much rather have stores like that than having to go to Tractor Supply.
Sure, it could be done unethically, but I don't think there's any intrinsic evil about it.
I also mod SDV so I can muck with the time. And make the fishing easier.