Whilst being nowhere near posh enough to own a Russell Newbery, we joined their club members for an organised trip from Ellesmere Port into Liverpool (as crew). It was amazing, there was about a dozen boats going, with the first having the pilot on board. I would think a pilot would be an essential - I'm not sure I would want to be out there on my own though, as there are times when you are a LONG way from the bank. We were told to creep up the south shore until we got to a certain point at which we had to turn to cross the Mersey. The tide was incredible and we watched the boats turn across it and immediately end up well behind us.
You will need a survey to get onto the MSC. I would talk to the RN Register - they were a very friendly and helpful group. The moment of arriving in Liverpool Docks was amazing though and a great time was had in Liverpool. Not one to be taken lightly, but well worth the trip