Is it possible to configure Opus Viewer to display images as sort of Photo Album ? I am referring to simply displaying, say 4 or 6 images at a time.
It will allow me to "manually" step through hundreds of images in a folder quicker, while at the same time, I have manual control of how long I want to look at each pictures.
Isn't what you're describing the same as using Thumbnails mode in an Opus lister?
The image viewer only displays one file at a time but a lister Thumbnails mode will show you multiple images and you can make the thumbnails up to 256x256 (or down to 32x32). If you turn on the Thumbnails toolbar you'll find a Thumbnail Size slider which lets you adjust the size on-the-fly for just the current window. (To change it for all windows, use Preferences.)
Although I think it's not not exactly what you are asking, the stand-alone viewer actually displays the list of selected files or all files depending on how you invoke it.
If you just highlight, say 6 images, then click the view button in the default toolbar, the viewer will open and display only that list of selected images.
For what it may be worth here, and it's only my personal opinion,
I find the DOpus standalone-viewer and lister tumbnail display infinitely preferable to Visa Photo Gallery.
In addition to properly displaying an image without an arbitrarily added yellow cast,
the Standalone-Viewer properly displays 48 bit tiff images rotated into a new 48 bit tiff using Paint Shop Pro.