I have listened to many people smarter then me say if it cash flows its great, if the CoCROI is below 12% skip it, 1% rule, 2% rule 50% rule etc. 

Can I skip the two things above and just get the Sentri access?

My future goal is to open a bed and breakfast and airbnbs!

They skipped it and ended up getting a home that was closer to being done how they wanted it. 

They have a 7-day free trial as well, so take advantage of it (But don't use their skip tracing service as it's low tier quality data). 

Or...You can pull cash transactions, skip trace those buyers, and contact them and ask if they're looking for more properties to add to their portfolio. 

Another easy way is to continue to drive for dollars if you aren't already, look for houses that are distressed, write addresses down you see that are good, you can skip trace, send a mailer, letting them know you'd like to make them an offer.

The process is fairly simple though but you might get into trouble if you don't take it seriously or skip steps.

I'm thinking maybe I should hire a skip-tracing company because the neighbors stated owner had one son.

Unless you are planning on actually selling houses skip getting your license-between the education requirement, background check, application fees, board dues, MLS fees, desk fees, fees to your broker ,E & O insurance etc,. it is probably a lot more expensive than you think and if you are buying a property you aren't paying a realtor anyway, the seller is.