In the event my landlord is interested in selling, I was wondering if I could add value in the short term by, say, converting part of the garage and/or covered porch into a bathroom and maybe a bedroom (currently 3 bed 1 bath).

That beaing said you should focus on buying a 2-4 unit Multifamily the more doors the more cash flow. 

I currently own a duplex that is cashflowing at 14% COC for 2 years and i figure the more doors the better.

-Doesn't want to use one agent-Thinks agents just use Zillow and open doors-Wants off-market deals under 10% market price despite insulting same agent and wanting to use multiple at the same time-But no rush to buy, no timeline-Also open to multiple types of homes and within a few hour radiusI am sure you won't like my post but I like being honest on here.

2) Buy a few out of state properties over the next few years, through a well vetted turnkey provider like the one I mentioned above, which should more or less break even or give me a little bit of cash flow, and since I'd end up with a few doors my risk would be a little more spread out? 

Appraisal fee seems very excessive if this is not more than 4 doors. 

I have 3 doors that need to be managed in Jax and Citrus Spring.

I have 3 family apartment building and a SFH with 4 garages, 1 shed, and 4 outside designated parking spaces for sale for 1.75 million. 

But anyone who books that is either going to pay next to nothing to be 25 minutes from all the stuff to do, OR, they will book it for the amenities and probably plan to stay in.Probably 90% of my guests in nashville have booked for location.

MLS has it as a single family residence, 3 bedroom, 1.5 baths (actually has 2.5 baths), approx 1500+ sqft, 9k+ lot size, 2 car garage, back yard.