Did the proceeds from the sale count as short term or long term capital gains?

. $200k fully financed with 8% heloc, 30 year term is $1468/month.  

What should I be aware of in terms of fees, timelines, and potential compliance issues?

From what you’ve described, it sounds like you’re more focused on long-term appreciation and future benefits rather than immediate cash flow.

If you do not find success there, there are some online companies like SpaceJoy, Decorilla, Havenly etc.

There are good relations with the neighbor so this likely wouldn't be terribly difficult to pull off, but I haven't ever developed a property from scratch so I would definitely like the opportunity to partner with someone on this to help ensure the success but first I want to finish the smaller property to have sufficient funding available if it is needed.

Looking at this property as a long term rental strategy.

By working closely with hosts, legal teams, and city officials, PadSplit successfully defended its model, ensuring continued housing opportunities for those in need.With this case setting a precedent outside of Atlanta, it strengthens the argument for more flexible and inclusive housing policies.

The best amenities for Airbnb in terms of ROI often depend on your target audience and the location of your property.

Best of luck with everything it seems you have the experience and workmanship needed to be successful!