This is where it gets complicated.

My mother in law wants to buy a new house, i own 2 SFRs and would love to possibly partner with my in-laws (we have good relationship lol) with their old house to rent it out, and split the profit. or somehow get this...

I am just learning about DST however it seems like it locks up my funds and is complicated compared to what I am used to which is simply managing rental properties. 

That might complicate things.

@Philip OlivierYour tax profile is a little bit more complicated and such I think you should hire a professional(I am a little biased).Since you make $100,000 from your full-time job - you should be eligible to deduct the losses(if you have them) from your rental property so long as you don't have significant income from other sources including the short term rentals. 

It will be considered a civil matter with eviction as the only optionThe police are not social workers or a judge looking for an ad hoc solution to a complicated problem.

It gets more complicated if taxpayer used the proceeds for multiple "buckets".  

I was taught that a judicial sale will wipe out all leins except federal. 

It sounds like you are over complicating it with the assignment.

I am curious if I am understanding the only way a tenant in Texas has a right to withhold rent is if there is an amicable agreement between tenant and landlord or if the landlord fails to remedy a problem with the house that impacts the the safety and health of the tenants.I am trying to keep things simple and not complicated on this question. :)