I realize a lot has to be worked out, but tokenization through blockchain eliminates a lot of legal documentation issues once established.  

i'm in the same boat....also has a florida deal in the works with title issues coincidentally. 

Your client should consult a real estate attorney to draft an agreement with the ex and ensure there are no legal or tax issues, especially since this is an investment property.

If you are a legal property manager in your state the owner should have the unfettered ability to allow you to act as his/her agent to enforce the lease, whatever provisions they may contain plus whatever your state laws allow.

We issue each investor a monthly check for their % of each monthly mortgage payment. 

Class midwest issues. 

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

What happens during periods when the demand for legal work is lower?

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

That will be an issue if you change it to try and make it contingent on financing.