[galaxyflorida]

Yes, there will be staff on board. They'll be a person in the the little cafe area, and then a train manager will either be in the carriages checking tickets or in a little 'office' which is next to the cafe.

As Crewe station is managed by Avanti there should be signs on the platform indicating where roughly each carriage will stop.

As for upgrading to first class, I think that on a weekend the prices are fixed. I know from Birmingham to London its £20 each, so would presume from Crewe would be a little bit more. Not sure what it would be during the week though!