Wading is permitted - steep banks so wading is pretty much essential (chest waders).
Hotel beat starts at the bridge and runs down stream for a good way - mile or two I'd guess but more than enough for a day's fishing.
The stretch between the railway bridge and the Wye isn't really Grayling water - very slow. Your best approach is probably to get a lift to the bottom of the hotel stretch (the car Park at Duke's seat) and work your way back upstream to the Wye confluence. The streamier water is very good for Grayling.
Derwent's absolutely stuffed with fish. John Tyzack gives lessons on that stretch of the Derwent -
http://www.johntyzack.co.uk/
Keep meaning to book myself a lesson.