In general, in a 1031 exchange the adjusted tax basis for the relinquished property becomes the tax basis for the replacement property.  

there is definitely a benefit to holding onto properties forever, but you can accelerate your profitability and return on the original investment much faster if you sell those properties and exchange them into a profititablemulti family in a growing market

And whatever path is easier to do a 1031 Exchange down the road. 

I'm a drywaller and painter by trade, and would come paint a unit or whatever you might need (within reason) for free, but in exchange I want to go see what a day in your life might look like and find out more about the market, and then we go out and hit up a top golf or something.

I've found FCI Exchange and LoanMLS to be good resources to look at notes. 

Once you're ready to put your feet up, 1031 exchange those SFR rentals into high cashflow multifamilies, apartment buildings, trailer parks, etc.  

You could also looks at a 1031 exchange if you feel you have opportunities you can jump on in a timely matter.

Once you complete your DD and work out a price it is a matter of signing a contract and exchanging your money.  

Am I personally comfortable retiring 5 years later than I otherwise could in exchange for going to Europe, South America, and Asia in the (hopefully) first 1/3 of my life?  

. ----------------------------------------* as per note above:b. holding meetings of its members or carrying on any other activities concerning its internal affairs;d. maintaining offices or agencies for the transfer, exchange and registration of the foreign limited liability company’s own securities or interests or appointing and maintaining trustees or depositories with respect to those securities or interests;k. transacting business in interstate commerce"