Hey there, you bring up some great points. If you make your channel your name obviously it's going to be very easy for anyone you know to stumble upon you, if it's more a business or brand or even just some goofy name it's highly unlikely anyone will find you unless they are searching for the type of stuff you make videos on.

As far as not going on camera there's plenty of people who do screencasts, there's one particular creator on Youtube and Vidme, forget his name but has kind of a gangster persona and wears a bandana over his face.

I will say I think it's easier to grow a following and get people to watch videos as we as human beings want to make connections with people, we want to see people talk etc so I think you can go further and go further quicker by going on camera as it's easier to make a connection with your audience but like you said there's ways to get around that.