Camera vs. PBR vs. RT

[mtldesigns]

I've had more issues with getting quality views than I did designing the house.  Walls that glow, doors that are black, white tile showing silver, just to name a few. 

 

To get the views that I need for this project, I'd like to stay with PBR.  So here is my question, the 3 views attached (camera, PBR and RT) are from an exterior pool shower, under deck (house on 15' pilings).  When I PBR, my door is black, why?  I have one light out here and it has been on and off, with the same result.  The sun lums are set 75k, sun follows camera.  There isn't anything black that its pulling from.  Also, this is a beach house, so taking a night view to get the white trim is kinda dumb IMO.  And when I try and run as a RT, the white tile turns silver (this view was stopped after 4 passes on why its grainy)??         

 

Curious, why does PBR work better at night anyways?  That has never made sense.  My gray walls in my home look gray in the daylight and at night, so why can't PBR be just as simple. It seems like the only way to correct PBR issues is to toggle sunlight, which is not right, because sun light and its shadows add to a view.      

 

The last pict, BATH 1-3 is from just inside that shower.. all white, PBR.