If the mazes are on-park, that I really do think that they should be free to all guests if only to eliminate the sour taste from the mouths of those people seeing walk-on attractions, only to discover a separate charge for them. I don't think that's fair on visitors and you don't see the likes of Halloween Horror Nights, Fright Nights et cetera with such goings on. Over at hotels it's a different matter as the mazes could be seen as part of the 'resort package', as opposed to theme park, where everything should really be included in a (higher?) entrance price.
I think there should be more stuff going on at the park itself. Terror of the Towers is absolutely excellent and the Zombies! Scare Zone was a nice step forward, another scare zone (Haunted Hollow? Th13teen path?) would be excellent along with the return of some of the 'live' attractions of old, children's entertainment, lighting, Halloween 4D show and possibly a laser display? Then there would be enough on-park even not taking into account the hotel mazes, which could (and would) be heavily advertised regardless.
Perhaps optimistic... definitely optimistic. But that's what I'd expect from the UK's number one theme park... it sounds as though Scarefest was easily overshadowed by Fright Nights in 2011.