Can't help you on suites. As for side of the ship, we took the cruise last year (when it was the Viking Danube from Amsterdam to Basel) and it made zero difference what side of the ship you were on.
The lowest cabins (D category) tended to look only at the seawall when we were tied up. But we were a C and sometimes we faced the port and sometimes we faced the water and most of the time the river is so narrow that it really made no difference. Only once did we moor alongside another ship. I believe that is rare, although someone else may have had a different experience.