Identify where the moisture/humidity is coming from.2.)

I had a new master bathroom installed and I have started to suspect moisture is gathering in that attic.

There is a carpet pad that has a moisture barrier that will prevent pet urine from penetrating the pad.

OK< so a house with plants on the wall to the second story (so moisture on the siding) and a large hole in the ceiling (prob water leak) is a minor repair and only $135K in Eureka?

It looks like you have good eve coverage over the walkway so moisture issues may be minimized. 

was the dehumidifier part of the hvac system to remove excess moisture?

If it's remediated then it is essentially gone unless the moisture comes back (that's the more serious problem; is the water leakage fixed?).

How do experienced investors view things like water/moisture in the basement of a property?

I've been there and this has been my solution. 1 fix plumbing issue2 spread lime (garden lime) thickly over affected area.3 let nature take its course our Florida sand sucks up moisture and nutrients in no time.

Suggest better underlayer using acoustical and moisture materials.While Vinyl is very tough and affordable, people will catch on that they used recycled vinyl (car interior) and limestone.