I am just curious if anyone thinks that the BRRRR strategy would work with Air BnB?

For about $6000 I can have a whole house unit that will give air to the whole house using pluming instead of ducting.

What kind of heating system-gas or electric forced air, heat pump, electric radiant?

The roof is new and the heat and air (two units) one is 7 years old and the other 4 years old. 

An unvented crawlspace, if not air conditioned, will most likely be a nightmare, especially in hot humid climate.

This monstrosity-in-a-tree is 97 feet in the air.

looking to finish a 18x12 shed on a concrete pad..it will have plenty of electricity ..finished drywall walls and ceiling...windows..beautiful matching outside finish...this will be in Cotswold neighborhood.. it will have heating and air conditioning...no plumbing no bathroom.. 

So, we had an electrician come over and to our surprise, due to a dedicated circuit that was installed for the air conditioner unit (needs repaired, but circuit is fine), the process of wiring/installing electric baseboard heaters is fairly cheap and easy to do.Having said that, I am racking my brain for possible pros and cons of adding these heat sources and being able to call these "bedrooms".

Phillip,Check out Cozy for automated rent collection.Check out stessa dot com for free income and expense tracking software. 

If you have to worry about someone stealing your air conditioning unit, you are probably investing in the wrong location.