I've seen data that includes roof type, roof cover.. but not roof age.

But I make sure that I have the following in place from contracts: (1) I get the late fees (2) no upcharged on repairs, (3) i get to see the contractors invoice, (4) i get access to all data. 

I'd get a task rabbit or your PM to take a picture outside every month to help ensure the yard is maintained...watered, weeded, cut.   

But for the number of homes that did get flooded, there were several that didn't - up to you to decide if the glass is half empty or half full.There are ways to mitigate your financial risk - look for properties outside flood zones (keep in mind that Harvey saw flooding in areas that were considered not to be flood zones but I'd argue that these maps become more accurate the more data we get).

Data rabbu is another good site to get projected monthly revenue. 

You'll want to have the confidence of data to back up your decision when the going gets tough.

Get some help to ensure you don't lose your money.

Ideally, create a separate gate to be used just by the ADU tenant to access their unit.Natural light: ADUs are small and one of the best ways to make these spaces feel bigger is to ensure lots of natural light is flowing into the unit.

Service them once a year to ensure they are clean, operational, and safe.

I obviously dont know each state, but the only person Ive heard mention on BP that it was legal in their state was a Florida agent.I'm fairly confident that it's technically legal in Ohio but my understanding is the Division will scrutinize the heck out of you and require a ridiculous amount of disclosures to ensure you make it clear to the seller that you are going to make a whole bunch of money off of them.Like you literally need to have them sign a document that says something to the effect of my commission will be anything I can sell your house for over $100k.