I would also suggest letting them know what the requirements are prior to the showing, and possibly even allowing them to sort of fill out a questionnaire and making it known that failing to meet one or more of the requirements could result in denial of a tour however, everyone is encouraged to apply.Quote from @Emily Mohr: Thank you @Charles J Sabo, @Caria Mitchell, and @Matthew Becker! 

I suggest using a service like Mayistay.

For example, population growth in certain neighborhoods and increased investor activity have created opportunities for both long-term rentals and value-add deals.If you’re torn between wholesaling and holding long-term rentals, I’d suggest thinking about your long-term goals.

I would suggest going as big as possible in the beginning. 

Can I beat inflation.Paying off a mortgage does none of those things.I'd suggest if you are able to pay off a mortgage, you instead use it to buy another "cash flowing" property. 

I suggest a neutral tone when you send your letter and hope for the best.

I'm seeing a bit of data from Insurance.com and NerdWallet that suggests Oklahoma has the worst insurance prices in the nation.

Suggestions on learning more about contract for deed?

Could you kindly suggest the best resources or methods to identify comparable properties in the area?

Look to other members suggestions and, definitely interview your Realtor choices before going headlong into an agreement.