I have my eye on a SFH fix and flip in a neighborhood where house prices will vary from 1.2M  to 600K depending on how extensive the flip is.

Depending on where you’re investing, you’ll get varying degrees of cash flows and appreciation.

Employment laws tend to vary by state.

I know rates will vary widely based upon park location, size, infrastructure, etc., but I’d love to understand what other folks are using today when making an initial offer to purchase.

The numbers likely vary by location and of course by property! 

Most people I know figure 8% of the gross rents for repairs, but maintenance costs vary significantly due to the current condition of the property and deferred maintenance.

Rehab can vary on how distressed the property is, we've had rehabs for flips around 40-80k and at times even lower or higher and rehabs for rentals ranging from nothing needed or 10k to up to 50k due to the amount of work required or if there was an issue with the contractor.

In terms of points almost every hard lender has them and they vary from borrower to borrower and project to project.

Check with your lawyer as this will vary state by state and I have not worked in NY yet, as well as current status of evictions with Covid.  

Mileage may vary for cabins with more bedrooms / multiple fams, but still worth the experiment imho.