Steve, I thank you very much for your offer. I'll think about but first there are 3 things I want to try:
If the ambiance of the whole scene is as dark as I have planned, I think I can delete all second rows of cans which I only added to be sure to have no gaps in the renders.
And I'll reduce the number of faces of all parts to the half so that should help very much.
The original shelves are for wall mounting if you look closer. I'll change to simple wooden shelves in a simple rectangular "Ikea-like"
construction.
After that the model shouldn't be the same 300-500 MB mess as it is now
And after I've done these basics I'll absolutely appreciate your support and suggestions. But it can take a week or so.
I am still no modeller, I am guided by instinctual and blurry ideas rather than experience or knowledge... and I have too many project parts in the pipeline at the same time
...you'll see in the animations area... soon...