When we purchase a property, we always look into what permits have been pulled in the past to better evaluate the value and integrity of the structure and it's surrounds.You wouldn't need permits for aesthetic elements such as: Cleaning, painting or refacing cabinetry.Replacing cabinet knobs and drawer pulls with simple, modern hardware.Installing new countertops on existing cabinets.Replacing backsplashes.Updating lighting fixtures.Updating plumbing fixtures.Replacing floor coverings.Painting over existing interior and exterior surfaces.

There always seems to be debate about investing early to capitalize on compounding interest vs paying off debt ASAP.I have a significant student loan debt but my wife and I have been able to put ourselves in position to pay it off in a little over a year from now (using about 50-60% of our combined incomes to pay down loans).I don’t have a job that matches in a 401k, but I have a Roth IRA.

Those fittings work on practically every type of modern supply pipe, except galvanized, which requires a threaded transition. 

Am looking to buy something in the Tulum area that will be used as a vacation home but also rented out via Airbnb (mostly rented out for a while as we’ll only probably be able to go down there 3-4 weeks a year combined max for now). 

For your first project, I'd recommend identifying something built after the mid 1950s that has more modern building standards.

I am looking for a brokerage that is investor-friendly (having investor-minded agents, and a focused investor clientele), use more of modern marketing technology, provide training or mentoring for new agents, and have agents and brokers working in office to bounce ideas.

I'm only familiar with DC's rules on primary homes but it does sound like you're trying to combine a hotel with a primary home Airbnb without following the rules for either.

After building on each lot we’ll walk with more money than we have in our retirement accounts combined.

I am new to REI but I live in Flint, MI and my house was under $70K (mid-century modern behind a major teaching hospital and less than 10 minute drive to 4 colleges / universities).

you say that you have two large bedrooms and two that should be offices...any chance to combine the two and make it 3 br house?