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?

Ideally, this would be just one step in a larger plan to grow into multiple rental units over time.

At first, he was anxious about having multiple tenants under one roof, but with the right house rules spelled out up front, it turned into a solid monthly cash fow for him.

I am a long-term investor with a buy and hold property in Brooklyn, NY and I also own multiple lands in Florida and Mississippi.

The "Set it and forget it" mentality, I think, will limit your listing big time.I do all of the pricing across multiple listings. 

Remember, I sent a signed and amended the agreement on November 28th, sent it to them for signature, received confirmation of their receipt, wired funds, requested multiple times they send me the fully executed agreement, never received a fully executed copy back from them and finally was questioned by them yesterday as to why I altered the agreement (meaning there was no meeting of the minds since it's therefore proven that they didn't even look at it).I have rescinded my offer to enter into a contract with Estate Legal for lead generation services and am now seeking a full refund, including my cost of wiring the funds. 

You could also consider a reverse 1031 exchange, where you buy the new property first.Make sure to identify multiple properties (up to three) to keep your options open, and try to negotiate longer contingencies with sellers.

If done right, a well purchased flip will have multiple exits.

At the time, just about everything was going for much higher price per square foot and with multiple offers.

We vetted a  handful of "turnkey" companies and REI Nation was the best in terms of reviews across multiple sources.