Obviously, not the parent, but one doesn't need to enable things like newrelic, scorecardresearch, xignite, adroll, etc. in order for a website to function (if so, it's not worth it). I think the basic rule is not to allow any scripting from any domain that isn't directly related to the main domain one is on. Things like ytimg will have to be enabled in order to use youtube, for example, while googleadservices and googletagservices will not.