Why add unneccesary noise channels? Not everything is black and white. Open up when it makes sense to be open, and be stealthy when it's appropriate.
As for unneccesary noise example, that would be feedback of people whose feedback I do not value.
And as for edited and added last question - it depends. :)
Whatever your methodology is, at some point you can't parse more feedback, and it's then noise, whatever its contribution is.
Dilluting my karma like I just don't care! :)