And preparing a building site and installing a driveway are further considerations if I even decide to build something there.

Bonus depreciation is 60% for properties placed into service in 2024 and 40% for properties placed into service in 2025.https://www.biggerpockets.com/forums/51/topics/1113749-cost-segregation-faq

Most service or trades people us included increase the rates for customers we don’t want.  

Real estate investors often find themselves working with many providers between insurance, financing, property management, tax preparation and strategies, etc.

Find one that can be custom to your needs, has flexible pricing, no long-term, high-cost memberships and excellent customer services to determine how to best market to your leads.

Do you have someone that manages it all including bookings and customer service or just specific parts like cleaning only? 

They have good customer service, good online access, and take series LLCs.

I’m considering having a lawyer send them a certified letter, though I know that will still come with a significant fee, which is still preferable to full service.

Anyone investing in real estate needs to be prepared for that.It sounds like this investor was able to make significant progress with this tenant to get caught up.

Title company will need formation docs, and operating agreement to prepare deed and title docs and lender will need formation docs and operating agreement for lien search and loan docs.