I am planning to purchase a property subto the existing mortgage (50k left) and current tax lien (65k).

Unfortunately, the city is currently not accepting any new 'Short Term Rental' permits, but they are accepting renewals for existing permits.

I'm a big "life doesn't exist on a spreadsheet" guy, but I'd suggest letting the numbers influence your decision rather than the hesitation to let the once in a lifetime rate go.

Much more affordable with an existing building like a garage. 

As you get further away from standard real estate practice, the risk is increased by a “legal” risk that your protection may be interpreted quite differently than you expect by a court and that the subtleties of the protection a mortgage or trust deed document provide with established law and court decisions handed down for (in the U.S.) 250+ years is not existent. 

You need someone who clicks with you personally before engaging in a mentor/mentee relationship with the dedication and stress that may be involved.Where to find a mentorStart by looking within your existing network.

Thanks Jorge build new don't buy new and don't buy existing. find your own land, entitle it, control the full process, get architects, zoning attorneys, roll your sleeves up it isn't easy but it's big money. 

Lenders might have different policies on how soon you can obtain a second loan, and it may depend on factors such as debt-to-income ratio, existing debt, and property cash flow.

Exactly, and now I'm wondering if where I saw this was a presentation where someone manually analyzed the data and produced a report because nobody seems to know of a tool that does this.I definitely saw it though, so it exists somewhere...

Similar developments exist on the Gulf Coast, but I believe there is still an opportunity for expansion in this area of Real Estate.