It looks like in your state (CT) like my state PA that electricity is de-regulated meaning that the consumer can actually choose the company that generates the electricity separate of the one that maintains the physical lines and handles billing.

As others mentioned, including goals in your post is huge that way others can tailor fit an answer to your specific scenario.

Has anyone successfully built a full rental unit in a single family development with an HOA, specifically Douglas County?

While many HMLs will not lend to a newbie, the industry is becoming increasingly competitive, so a growing number will. 10% down should not be a lot to ask.As hard money will cost more than your HELOC, you'll need to find a better deal.

A lot of great investors on here and interested to hear your thoughts specifically as to ADR's and occupancy as well as philosophy on occupancy rate.Can share my listings if needed

While private money isn't highly regulated at the federal level, there are subtle nuances to be aware of in each state that may trigger your loan becoming a security and then the SEC would have regulations to consider.

Have a specific SOW and a Valid State contract.

Amount of rent, due date, security deposit, house regulations, and any other pertinent information should all be included.

Im not familiar with the specifics of the USA + Mexican tax treaty, but this article is a great place to start: https://www.cpasforexpats.com/post/us-mexico-tax-treaty#:~:text=The%20US%20Mexico%20tax%20treaty%2C%20signed%20in%201992%2C%20serves%20as,according%20to%20their%20respective%20laws.

I am located in CT and NY, but not state specific.