No, nothing else is important. It _does_ help to be aware of these issues, such as impedance mismatches. But all problems will result in bad sound, so your ultimate judge is still your hearing.
Forgive me.
Forgive my ignorance O Masters of Sound and Fury. But other than sound quality, are any other factors significant when matching separates from different manufacturers? For instance, output voltage or input sensitivity or input impedance of a pre-amp when connecting to different corresponding values of another brand of amplifier? Any technical issues, simply sound, or nothing to be concerned about?