That is who they write that article for so they can sell subscriptions. 

If i sell my SFR rental for $450k and equity is, for example, $200k...Can i invest 100k into a new SFR worth $275k and invest the remaining 100k into a sponsored DST or TIC (which deals are usually multiple hundreds of thousands of dollars?

. -- They have fixed fee structure to compare with anderson advisors without any blatant selling tactics https://www.kbkg.com/" class="redactor-autoparser-object">https://www.kbkg.com/https://go.empiretaxusa.com/61...If you attend any tax-wise or other 3 day events with anderson which costs $197 + travel expenses you will get enough knowledge on how they operate and you should be able to understand what LLC structure is beneficial, also they have a large collection of online videos with plentiful of information on youtube and tax tuesday webinars.

Conventional (only Freddie Mac See Section 5102.4 of Freddie Selling guide).

Right, but to get an ARV close to $130k, you'll probably need rent to be close to $1,300 unless you can sell it to a retail buyer, which could be a big risk on its own. 

It could be that you just need to sell this property as it is not actually an investment, but something that is causing you to lose money by not obtaining occupancy, and certainly not getting any type of appreciation, equity, or ROI.

In theory, you could refinance the property and buy them out OR you could sell your interest to them.

A con would be that a cost segregation strategy was implemented, and the investor sells it within 5 years with no intention of doing a 1031.

What cap rate is the selling asking?

They sell you a package to enter and then find you people to stay and never paid you back!