[deanhills]

You don't need to be logged-in chrome in order to use their extensions, but they do ask you to log in to your google account when you are up to download extensions from their web store. I do remember there used to be some youtube video downloader extension for chrome as well, but it seems like they deleted it from their store for some reason.
I have to agree with you that chrome loves to have the hold of all of your information, and this is the thing which annoys me too.

My experience was different.  I could download an extension that was a free extension with Google, but during the next session it was gone.  Only way I can keep it for the longer term is to log in and to add the extension under my account.  I definitely want ZERO connection with their Web store.  I don't want my pay information on their records.  I have a serious distrust of Google and the level of its care of its customers.  Google is there to make big bucks for its investors.  That is its bottom line.  FireFox probably isn't that innocent, but it's the lesser evil of the two for me.  I've lived many years with FireFox.  My compromise with Google is to use it as superficially as I'm able to do - it's probably tracking my IP, but I'm not giving it my personal info as far as I can help it.