You would need to some your research and decide which route suits you best. 

My current purchase (closing in February) is a luxury cabin that will be an STR.  

The spacious primary suite features a private full bath with double vanity, while the flexible layout provides options for bedrooms, an office, or hobby spaces.

S-Corps are better suited for active income (e.g., property flipping).

If you are only living there for a few months each year, why not look for a home with a suite? 

If they file a suit all you have to say is the concessions was for any and all issues which most likely it was.

BiggerPockets is an excellent resource to kickstart your real estate journey.I recommend that you take the time to define your financial goals and always keep learning.From insightful podcasts and informative blog posts to interactive forums and detailed guides, BiggerPockets provides a comprehensive suite of resources designed to empower you with the knowledge and confidence needed to navigate the market.

While some strategies may work here, those strategies might not suit you.I don't personally do MTR, STR, co-living, or other nuanced strategies.

While I’ve seen QuickBooks mentioned in forums, it tends to be more expensive and seems better suited for larger portfolios.

Your other questions are better suited for an attorney to avoid misinformation.