For property owners with out-of-state investments, is it necessary to keep all receipts and invoices for write-offs during tax season, even smaller jobs performed by the PM's handyman?

Most lenders have seasoning requirements, so you would need to own the property for 12 months to obtain a loan based on appraisal rather than lower of appraisal or purchase price.The longer the period of since property purchase the more likely an appraisal higher than purchase price.The exception may be a "hot" market where prices are moving up sharply almost every day. 

Relying on general ideas is dangerous when it comes to taxes.Read this older thread to see why this area is far more complicated than you might think: https://www.biggerpockets.com/...

There is nothing like a “fine touch” of a beautiful kind hearted lady and a gentleman. 

It would be helpful to understand the seasonality and other factors that affect bookings.Also, how long have you been a host, and what have you found to be key to your success?

That may also give them some time to make repairs, upgrades, or setting up new marketing efforts to prepare for the next busy season.

If, while running your numbers, the returns are within range to your criteria, do not lower the expenses to "make it work", but just know that some months may be higher, some may be lower, and if you have the cash reserves to support a higher bill or unexpected repair, then the underwriting at least helps you mentally prepare ahead of time.Any calculator, based on the inputs from any noobie or seasoned professional, will NEVER be the same as your actual numbers.

The only concerns that we have are insuring older non code homes and Flood Insurance.  

Tax season!

Consider listing during peak seasons when demand is up, and you might just be the early bird that catches the worm!