I say "no" to all of it, unless I'm at a particular web site, say Microsoft, downloading something and the request is coming from Microsoft. In other words, if it's unsolicited, I say no. I have no idea though, if this sort of request can spoof the IP address of a legitimate request. Always better to be safe than sorry. Sometimes I sacrifice convenience for safety, but I don't have a problem with that. It seems to me that too many convenience features just open you up to abuse from someone trying to gain access to your computer.
Just my 2ยข