Most lenders will finance a portion of the property and 100% of the rehab costs.

Furnished mid and short term rentals will cash flow if managed correctly and you find the right location and property size. 

Depending on loan size and what the DSCR ratio is, I have a lender that would be 6.88 to 6.99% with no points with a 680+ credit score and 20% down. 

It's essentially financing a portion of the transaction by increasing the purchase price by the contribution amount. 

Unless the place in an amazing location that couldn't support a full size home, you are better off doing a regular place.A tiny home isn't considered real property.

If the landowner throws in the land and you get another investor to fund the construction you would value each portion on their side of the 50% pari passu and split all cash and sale proceeds accordingly along the same lines.If landowner puts up land and cash go 50-50 model.

I believe your assumptions are correct, only there is no requirement to buy again for the primary 121 exclusion portion.

There are companies spending $100k a month on mail and all the smaller sized companies / people all get their data from same sources (like Propstream).To me it didn’t make sense to use the same info as it is extremely difficult to have any type of advantage

It's not that big of a problem if the zoning allows for 3 units on a property of that size, however in most cases like this the conversion would have been done illegally or at the very least is no longer a conforming use.The shared water meter is pretty typical for multifamily here in Tampa.

Provide four to five copies of drawings size 24"x 36" and 11 each Site Plan/ Boundary Survey.