I use ExpressVPN. It can be installed directly on routers that support it (I do not have a router that supports it, so I did not do that)
#1 I load the vpn software onto the items I want to use it on. I have it on our iphone, android, surface laptop, firestick, home computers. When we go on trip’s I find it very useful. Sometimes when using it, it will freeze and I have to turn it off and back on. But it is very easy.
#2 I have no Idea, I do not use those type of features. I have all my passwords on my phone in an app that does not have any access to the internet.
#3 I have been using ExpressVPN for about 10 years and am happy with their service, my wife refuses to cancel it so it has become a must have addition to our network.
You got me thinking that there should be a single point through which a VPN can be shared. I googled a bit, and there are routers that can be configured to use a VPN. I have not done any real research, but you might look into that.
I use Private Internet Access and have done so for many years. I have it installed on my iphone, MSFT Surface Pro that I travel with and on my desktop at home. It’s been fast and reliable. No issues that I can report except that it works well with no problems in all the years that I have had it. hth…doc