What is the proper way to switch between the Preview Panels? 

Whatever I try I always end up changing what alse is currently selected; hence making my Parameters Pallette jump from where it is at, which requires resetting.

Each of Poser's Rooms stores the palette positions etc., so you need to have visited each Room and adjusted everything before saving you preferred state.
It can also be useful to set a GUI dot for each Room in case something whacks the layout.

But what I'm asking does'nt have anything to do with wanting to switch rooms, nor create alternate GUI dots, or set a preferrance; I do'nt think?

Right now I'm working with 4 cameras at once(see attached picture,) because I'm developing a new outfit for V3, from Photoshop.  Currently the AUX_CAMERA 4 Port is Selected.    But Lets say I want to render the Main Camera port.  How do I just switch ports, without changing the selection of the Parameters Palette?

Just right click and then don't actually do anything with the context menu, it will change focus to each pane of the preview.

Thanks!

That's what I'm doing.  How do you get the Context Menu to go away?  I usually click on the top of the preview window, where the name of the file is. 

But this is just an extra step, there should be another way?

 The best kept secret in Poser: the shift key.
Holding shift while clicking will keep the current actor selection. That works not just for selecting preview panes but also for dragging in the window to manipulate things.

Wow, awsome, stewer; thank you so much, this was a huge help, yippee!