In addition, as a learning experience they can try alternate rent models such as rent by room, STR, MTR. 

Hey Alex, From what I am seeing and hearing from the agents/investors that I work with, a lot of investors who own properties are starting to transition from LTR to MTR/STR model, and housing professionals/nurses + the occasional booking on Airbnb/VRBO.  

well any pay 20k to a guru for that business model.. :)

I’ve had success in larger markets and smaller markets all over the US however this was because of efficient operations AND being proactive in finding companies to rent to (I employ the B2B model). 

And that educational out, you know, where you get a degree that offers you upward job mobility, where you move into a big house, and you drive an expensive, late-model car? 

I borrowed an underwriting model from a Real Estate Private Equity professional and it seems a little too complicated for what I am doing now and what I plan to do in the future.

It's a good idea to fund the "model home" if you plan on doing the "let me build your dream home" method, that way there is something to showcase instead of just plans and land.

It's a fine business model as long as you don't mind your tenants paying fees for your use of the software. 

Too few details to answer (Of course this varies county by county, all questions could be answered by reading the (zoning)/building code and/or clarified with a visit to the county planning office).but some clarifications because: lots of things are "tiny homes" but what you describe small houses "on permanent foundations" needs to be clarified , tiny homes could be:-stick built, see below. check your county code/planning dept-stick built cabins/recreational, a specific zoning and potential occupancy/etc restrictions but worth looking into where the zoning allows for it -hud manufactured homes (smaller singlewide perhaps 400sq ft 600sq ft minimum)-non-hud park models (on axles), ansi standards- other "RV's" built on a chassis:  organizations, state agencies, etc - will certify factory built (or sometimes inspected professional built) tiny homes on chassis - to whatever standards ansi, riva, dot/ l&i?

One time deal is not always a great business model.