I'm not up to date on the ticket options, but it is direct to Russell Square on the piccadilly line.

I have taken my wheelchaired father to Liverpool St overground and in most cases he was met by someone with the ramps, waiting by the car we were in. On a couple of occasions dispite staff phoning from our boarding station, this didn't happen and passengers lifted him and wheelchair off the train. I have never tried the underground with him, we always got a taxi from the station. The black cabs are not cheap but are good. The taxi rank is at the far end of the platforms. This might be your best way.

Sorry, I can't help with this one.

Yes! It’s open! 😉👍

At the moment there is heaps of space and it’s easy to keep 2 m away from others. How it will be at the end of August who knows Buses are slower but are pleasant. Again o crowds right now,. August may be different!

Hi Gwen, Yes, there should be trains running on Boxing Day. It is traditional to attend sporting events on Boxing Day so there are lots of people requiring transport.

You can use both.

Yes but at some stations they are hard to find. There is always someone to ask though

No, escalators only. The only tube stop that I found had lifts was the tube stop near Bakers Street.

The London underground is color coordinated so very easy to navigate. You will have no problem