Is there a reason why, after starting a new char, there are several places,
like Gallows Rock where there are sudden flashes of light? Like entering a new
room or at Gallows Rock starting down the first stairway inside the front
entrance? If I stop and creep right up to them everything turns a bright blue!

I never noticed these happening the other times I've restarted from the beginning.

Just like to know.

It sounds like a glitch in occlusion plain segments. Each room is separated into bounding boxes, and are connected by portals which are indications to allow other rooms to be loaded when in a separate room. The box around the room that indicates what parts to keep loaded when in the area need to be touching with absolutely no separation, is there is then you will blink into nothing for a slight amount of time. There is still collision in this apparent nothing, so it's harmless, however it's simply a glitch where the game things you're in no room and deloads everything for but a moment.