Vacancy rates to expect?

If rents are in a normal distribution (bell curve) like they should be expected to be then half of the units will be below the average and the other half will be above, you need more information before making a decision. 

My short answer to you is, I would expect about a 50% occupancy rate and probably not more than $200/night ADR (average daily rate) depending on the size, quality and location of your STR. 

Also if you have a partner that is family your first stop should be setting up an LLC or other documentation so that everyone knows what to expect before getting started, making money isn't worth getting into a feud with family over.

Energy efficient appliances are expected.

After years of a standard shower head, I expect some pressure and I feel like I’m drowning under one of those.

What do your tenants expect?

Based on the pictures, the repairs for 1 unit inside is way more than $5k that you expect. 

But you are also in a grey area where you will have to sacrifice something in your expectations.

I expect this to continue for a while.In the process of getting an average lot rent for the area.