With the amount of moisture it sounds like, the only answer might be dealing with it from the outside.  

I put masking paper on the base to direct moisture off the trim and onto the drop cloths.  

Laminate flooring is just moisture resistant.

The exterior walls are brick with yellow insulation and covered in plastic moisture barrier.

You can try to paint or skim over the top, but the moisture in the paint and wall compound may cause the wallpaper to bubble in different spots.

I would expand this not only to include regular rental properties, but  vacation rental homes, condo's, Air BnB's, etc  Start of with simple upgrades like key-less entry, smart thermostats, security system and moisture(water link) control. 

You've got to be careful to mitigate rain and snow in these window wells, because they will tend to allow moisture to migrate into your basement.

I'm from Florida which is obviously very humid so even the slightest moisture exposure can trigger mold growth. 

The only thing to note about this is that it has to be installed with the correct glue and no moisture.

More importantly in a bathroom you want to seal the drywall well so that moisture can't get at it.