rivnuts are a terrific jigger invented by mr goodrich or goodyear [always get these two mixed up] for attaching de ice boots to wing leading edges,
and yep the worst thing you can do to aluminium is attach it to stainless, apart from pouring mercury on it.
old rivnuts and incorrect fasteners can be a pain, but that's why god invented chisels and drills.
rivnits are definatly the best, however i speak in aircraft terms, so others may have experience with other fasteners.

