Suggestions on how to manage the finacial transactions for our TIC partnership without compromising either LLC? 

You don't want to be in the middle of a time sensitive transaction where your money is on the line and be working with someone who doesn't answer their phone or is slow to respond to emails.

So I put 22k into a 401k which will lower what I was going to owe.

(To give you some numbers we are all in at 2.1 million and it appraised just shy of $3.2 Million)This was a seller-financed transaction, the terms allowed us to use the ground as collateral and I brought partners in after I got all of the city approvals, and they took over the future expenses for the seller financing note and the other costs like engineering. 

The transaction costs of buying and selling a home (particularly the sell side) really eats into the margins.

It depends on what you're trying to accomplish... if you're not planning on investing in properties here, or even using the license part/full time to broker transactions - then I think you answered your own question. 

Would you Lower the rent by $200 per month?

Even if you end up paying for some of the mortgage, it will help you eliminate or lower your largest expense: housing.

What can be done to lower that DTI?

There are ways to lower your tax basis like having more rentals as an individual.OR you could have a C corp.