Best bet is to carefully analyze the zoning maps and regulations or just call the town and ask.

At the same time, little to no relief exists for rental owners.

Having developed a majority of my career in CA the regulations and red tape for construction and development are intense. 

Being new I would suggest started with existing builds but building small multifamily in a small town with a rental shortage could be a smart move (someone's gotta do it).

This policy will provide additional coverage above what your existing policy covers.

Two, you'll have a much easier time obtaining a mortgage product if you have a track record of W2 income.In the meantime, continue implementing the strategies you mentioned: save religiously, build your credit, pay any existing debt owed, etc.

You have to have an "existing relationship" if you are or you are working with non-accredited and sophisticated investors. 

This amounts to lost opportunity because if you had purchased RE, at the closing it can start producing return. 5) ADUs detract from the existing structure whether this is privacy, a garage, or just yard space. 6) this is related to number 1, but there are many more buyers looking to purchase homes for their family than there are RE investors looking to purchase small unit count properties.

I recently looked at an existing STR, but either the seller did not track the expenses or they did not want to provide them. 

I'll be honest with you, in my experience, I have never seen a Investor care typically about the existing financing, or what was owed on the property.