I seriously doubt that either auto (rain-sensing) wipers or auto headlights would be damaged by doing what they're supposed to be doing - actively operating when needed. Yes, they are subjected to additional "on" time, but cutting back on that to increase their life (by a tiny increment) also means that you may be failing to use them when safety is affected.
You're more likely to do damage by operating the manual switches more often, or with wipers, running them when they aren't needed (on a dry windshield). The wiper motor is not sitting there in some sort of standby "on" mode when the switch is in the intermittent/auto position.
I leave both headlights and wipers in their auto-on settings continuously. And I really appreciate that I no longer have to think about the opposite wiper-on switch direction compared to my wife's Mazda.