I have an engineer that travels across the country for me and does a site inspection, environmental phase 1 study, and a cost reserve stable.The cost reserve stable is where the inspector looks at all mechanicals and other vital systems to the buildings including roofs etc. and then models out based on when they think those items will reach life expectancy and need replacement.

Emphasis on marketable.

Mechanics of lender lending money based on your credit when you own 50% or less of the property may be a non starter.

I recommend investing in either new-construction properties with 10-year builder's warranties, and/or fully renovated residential properties with comprehensive renovation work (mechanical, interiors, etc.).

using a mechanical lock box works great for vendors, but I would never give a code, even a 1 time code with an electronic box or lock, you would be trusting the viewer of the property to turn off lights and actually close the door, I think you are taking a lot of risk this way, I had a vendor that left a door open, fortunately i got there before all the pipes froze, some PEX was frozen when I got there, Just be careful, I would Highly recommend paying a manager, they are worth their fee without question.  

Reasoning could be based on the mortgage repayment ability of your salary or ensuring you don't transfer the asset to your wife as a protective mechanism (there could be more reasons why they'd want her as guarantor but those are some major reasons).

Age of mechanicals, heating, plumbing, electric24. 

I used to be a mechanic and still have a decent space to do small repairs for a small clientel. unfortunately because I do allot of automotive work and I'm generally just loud by nature, I don't think that renting a room out would be a good idea for me. plus I typically have a hard time trusting people in my home. luckily we just paid off both of our vehicles so we are starting to get our overall bad debt down to a more manageable number. as things begin to become more stable, what are some of your paths that have lead to financial Independence?

Even worse is them filing a mechanics lien or judgement against you.

The emphasis being on encouraging.