A couple of points after reading this thread.
Someone mentioned that you were moored on "BW's water", and someone else said "but I already pay a licence to be on the water". You are actually moored over BW's land, ie the bed of the canal. That's what the charge is for.
BW charge the boat owner 50% of the nearest towpath side mooring when it comes to end of garden moorings. Why 50%? Because in using a mooring there are two benefits - foot access to said mooring and benefit of mooring over said piece of canal bed. An EoG mooring does not have access over BW's land - therefore BW charges only 50%, i.e. for the part of the benefit which relates to the mooring being over BW's land. It expects the owner of the EoG to charge the remainder to the boat owner, unless, of course, it's a mate or relative or indeed you own the piece of garden to which the boat is tied to.
BW may bill the garden owner for the 50% and the owner will then bill the moorer for that amount plus whatever they think having access across their land to the mooring is worth.
The court case was in 1992 and on the Lancaster canal. A subsequent one around the turn of the century also proved that BW had a right to charge for mooring over its property.
Occasionally, ancient wharf rights exist which permit 'the laying up of vessels', and because of this historical right it can be argued that BW cannot charge for a mooring at these locations. But they are few and far between!
As for witholding a cruising licence because on non payment of fees - I wouldn't count that BW wouldn't do this, regardless of David's views on unfair contracts etc. Even if they didn't, the outcome would be as follows. You apply for a licence, and because you're unable to declare your mooring location, you state you a CC'er. But you don't move like a CC'er, and so when it comes to licence renewal it is refused. See the test case on the G&S being covered in most of the waterway titles right now.
HTH, Eugene