I don't while out. I may make an exception if I found myself without napkins, but I always grab napkins, so I don't need to.
I lick my fingers at home, couldn't care less lol.
As far as licking to separate things, I will if I'm reading at home or whatever. I won't do it if I'm handling other people's stuff.
Like when you're at the market getting produce and you can't get the stupid plastic produce bag open, oh man I want to lick my finger to rub the bag apart, but I refrain, even if no one is watching
I don't care if other people do though, I'm not too weirded out by germs tbh