I have been thinking small office or retail (which I have experience in); larger multi family (10-20 unit), RV Storage, and have even thought about beach front hotel, or at least ocean view hotel.

New windows, kitchen, basement bath and adding a storage room/pantry in the basement. 

I have a 4 car detached garage at my property and I rent out all the bays for storage use.

This could involve offering a higher interest rate in exchange for reduced upfront costs or deferring payments until a certain milestone.If building right away isn’t feasible, consider buying the lot now with the goal of paying it off over time, and save up to build when rates and budgets align.

Median household income can be an indication of the area.It's not feasible to manage D-class remotely or with 3rd party management and make a profit.

We have not disabled ours or converted to gas, but Tenant must sign a Fireplace Addendum stating if they use it, we require a higher renter's liability policy with us as additional insured, rules on wood, storage, use, safety, they pay for yearly professional cleaning each year they are there, etc.  

@John Brown Running a short-term rental (STR) on a subleased property, often called rental arbitrage, is feasible but requires careful planning.

I just read Scott's Slow Flip book.....(1) Is it still feasible to buy houses for $30,000 -  $40,000 in this market?

No one is going to allow that and construction-wise, it is usually not cost-feasible for the output rent on such a large property.

Although we could continue to add to our Self Storage investments in the US.