At least start investigating the alleged current landlord more.Again great job on your vetting process!

Investigate new trailers or fifth wheeler's on the net or go to an RV show and look around, Best

A lot of it I will have to re-read/investigate for better comprehension ha.  

First thing I would investigate is if this is a Leasehold property and the agricultural requirements

I would advise to you avoid smaller 3/2s under 1000 sq ft, AE floodzones (expensive to finance), homes with sinkhole prior investigations/repairs, homes near busy intersections and homes near large mobile home parks.

I lived in LA for five years now, and after realizing that I spent over 50k on rent in this short period of time, I started investigating other options.

The realtor and the bank I am working with both know what I am doing and neither mentioned anything about any FBI investigations.

It may be cheaper than a professional inspection and I am not a big carpet fan, so you get that out anyway (especially if near end of useful life) and get to see the sub-floor, investigate thoroughly, and treat it if necessary (bleach/water, Mildicide, etc), and explore if there is a source (leak) or not, or if it was tenant negligence....Then you could go from there and call in professional help if needed and explore who should bear the costs, if any.I agree, there is some risk of rewarding the behavior (the complaint, by giving a new floor), but you mitigate it some by making the tenant remove all items from the room and endure some inconvenience.

Initial investigation reports that not electrical and no sign of arson.

That is why you need to take your time and be able to do a thorough job investigating everything.