Any suggestion what can I try next to diagnose this?

I've got under control, I just spend too much time diagnosing issues and responding to tenant requests for repairs, etc... 

A seasoned tech can diagnose virtually any problem within an hour.

It would be like trying to get car insurance on a totalled car, or trying to get health insurance as a smoker AFTER you've been diagnosed with lung cancer (in a world without ACA). 

. :) J/K, but sometimes someone who has fixed something in the past is the best person to call because they know what is usually wrong with this or that, and can come jiggle it back to life (instead of paying a lot of money to a new maintenance person who will charge you just for finding and diagnosing the problem...

I'm at a loss on how to diagnose the issue and handle the people.Both tenants are on month to month tenancy, so asking someone to leave is always on option, but they both pay their rent on time and cause no other issues.

During a prep for deployment I started to have some issues with the function of my hands and other joints, and eventually was diagnosed with autoimmune arthritis.

A diagnosed mental illness patient in a locked-down ward on suicide watch?

He does everything repair and make ready wise (including plumbing and electrical) except for HVAC and I already have a HVAC guy I use on rehabs that I'm comfortable with (Just text him issue and he goes out and diagnoses and fixes it without me having to be there).

It doesn’t sound like it.You have a relationship problem, and when it comes to relationships, the symptoms are often not too close to the causes.No one here can know enough about your relationship to diagnose the root of your wife’s unhappiness, but I doubt it’s real-estate.