if its the later I would get a copy of the county planning code that shows the homes were built legally and present that to the lender.but it could be HML just don't want to do deals in rural southern cities were sales can take forever and there is no there there .. if you know what I mean.HML can redline all they want as we know..

It is hard to comment without knowing the exact address.I like 72116 best but parts of the other zip codes are also good It depend on the location and occupancy + turn over in that area.You need a good property manager to work with that could give you feedback on specific location you are considering. 

You can give away a code as easy as a key.

Yes you do have to pass inspections and codes in order for your property to be rented out.

For example if your neighbor for $800k because a developer could build 8 units but with the new code changes slot homes aren't allowed anymore and the max you can build is 5, you're not getting $800k, maybe more like $500k.

The "better" zip codes  for investors are 02, 05, 11, 16, 24, 44, 46, 77.

The only access will be by a 6' ladder (no code where we live).

It's less precise than exactly calculating out the lifespan and cost on every major system for your exact zip code and specific property, but it's also more precise than using a round 5% of gross rents (or whatever).

Remember in these deals your not bound by any code of ethics..

.#1 recommendation is to check your city/county building codes to see if a tiny house would qualify as a residence.