It helps for warranty claims down the line.For GAF shingles, the 25-year warranty usually requires online registration.

His lease says they have use of the entire property for $X, if he wants to increase the rent that is separate from changing what they have access to.

You can probably find an online link about how extreme temperature changes are not the ideal way to heat a home and cost more in the long run.I don't know what the local rental rules are where you are, but look them up and see if you can give her notice. 

Most places have online property search tools that will give you the owner's name and mailing address for free.

Zillow and online county property records for sale prices.   

A local real estate agent with MLS access and market knowledge will be able to provide the most accurate rent estimate.

You can research these online.

If the search is correct you keep adding 3 months back and 1/2 mile out until you have them.The best value analyzer in my opinion is only accessible by realtors.

Check online reviews and interview multiple contractors to compare bids.

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.