Yaar I have to agree, but well if, ALLAH NA KARE, something goes wrong in the electricals of the car, they will almost instantly blame the fog lights installation. One thing I have heard but not experienced is, you can get them installed from a Honda tech and get the dealer stamp on your receipt. That way, it would be counted as a "Professional Install".
I have no experience though, sadly.
As for harmful, well I don't consider anything harmful. I have steelmate installed in my car, dil py pather rakh k lagwa lia tha cz its a must have. I can't stand by the door keying it all day with a bag over the shoulder and some books in hand.
I only said this since I know the fact of you being sensitive about the wheels you own. 
And nope. I don't have any such experience. though once, a friends car had a mechanical issue in the tappets. It was in warranty but he had CAI installed.
A tech at Honda Canal popped the hood, saw the short ram and exclaimed, "MAADIFYED HAIGI GADDI, kharab ty huni c".
LOL.