[Radoye]

No campaigns interfere with mods in any way.

Though some campaigns require specific mods to be installed to make them work, like maps and planes. But this is not the case with the payware campaign packs. I own several and they're pretty good, you get a ton of new missions and skins.

But in case you want to have multiple addons here's something you should consider:

http://www.enjoyr-page.cz/PanelPatche_eng.html