Hi Scott,
I haven't built in an unincorporated township, but I almost bought some land in one, so I've done a lot of research.
What I found was that you need to follow the OBC, as you know, but that there's no permit required, so no inspection. You're right that you need to get a permit for septic, but that's the only thing you need, though I'm sure you'd also be required to register any new well with the province.
What that means is that you can go ahead and build whatever you want and you'll not get any grief. If the building's visible from the road, though, and if it's clear that you haven't built to the OBC, you may get a visit. The office wasn't sure about that, but I'd try to keep any structures away from any access. The caveat here is that, if you don't build to the OBC and someone gets hurt or killed as a result, you may need to defend your choices. An unlikely scenario, but worth keeping in mind.
I really like the
freedom in an unincorporated township. There aren't any usage restrictions, so you can build a bunch of small cabins and rent them out or have a trailer park, etc. You will still be subject to any noise or other bylaws, so your idea of using the containers may be considered an eyesore if visible to outsiders.
You will need an electrical inspection if you want Ontario Hydro to hook you up. The septic is going to be an issue in many UITs (unincorp...) as most are located on the Shield and have very little topsoil, let alone
enough to pass a perc test for your bed. You'd have to haul in 20ish dump trucks of sand, but you can always go with a composting toilet or a
humanure system.
Let me know if you have any other questions; I may be able to
answer them. By the way, I enjoyed you in Kids in the Hall.