I am not sure mine are actually friendly. They pretty much stay away from me when I am in the pen but they aren't flighty and go crazy when I am in there either.
There should be no problem with you cutting her crest.
http://www.feathersite.com/Poultry/CGD/Houdan/HoudanCrev.html
The related problem of careless inbreeding is also at fault, as is a craze for a Polish type crest, which has led to far too much crossing with that breed. Ideally these French crested breeds should have large, well-formed crests...
Well, I don't have any hatchery houdan so I guess I wouldn't know. Mine have very nice crests but for some reason they seem to see a lot better than my Polish. I have never had any of them walk into anything anyway, lol.
I hadn't noticed my houdan honking(but I will listen again) but my buff laced make a totally different sound than my others. Do you have a picture, houdan don't usually have a crest that is that is as bad as a Polish or hinder their sight that much.