I'm sorry this happened to you, and it's one of the reasons that I try to use an estoppel agreement to cover clients who are inheriting tenants when they buy a building; not that it would have prevented this but at least it would give both sides of the story before closing. 

That usually prevents any complaints.I think the best thing you could do is extra padding upstairs.

Appraisal can prevent the policy holder from hiring an attorney if the outcome isn’t in their favor.

Use this as a productive measure to try and figure out how it happened,  and what you can do to prevent it, or prepare for it in the future!   

Or the old standby, "we really can't afford to raise the monthly fees just because some of our costs are rising, let's just postpone that preventative maintenance project until next year".

You need to ensure YOUR house is taken care of, and already should have preventative maintenance in place for exterior issues.There certainly are differing opinions here, but I would never, ever, write a two year term for a new tenant...for all the reasons you are dealing with.

I feel guilty using my free time relaxing after studying and not building something for myself, more than anything I want to provide value and not excuses regardless of my limitations but I also need to remain realistic to prevent myself from ending up in a situation I can’t fix.

There is definitely a stigma attached to mobiles and while many of the preconceptions may no longer be true the zoning ordinances prevent them in many of the places they could be beneficial. 

Do your HW on the front-end to prevent pain down the road.8.)

Obviously, a single room in a house will usually rent for much less than a 1 br apartment.If you do rent by the room, you'll need to develop systems for preventing and managing housemate disputes, keeping the common areas clean (a cleaner might be worthwhile), screening tenants to find people who will be good housemates, etc....there are just more moving pieces to sort out if you rent by the room (but, as a result, you usually make more money).