I would suggest that a lot of future developments at Alton Towers will be governed primarily by where it is practical to expand given the way the park has expanded over the past three and a half decades, not to mention the planning restrictions and issues that exist throughout large areas of the site. There is very little reason to expand into 'new' areas when there is opportunity to expand where power, paths, sewerage etc already exists.
This is an unfortunate reality - eventually leading to a park filled with coasters Six Flags style and a huge lack of attraction variety and no or botched themed areas. Sadly what has also happened at Alton Towers is that the park is polarizing its areas with extreme thrills (X-Sector, FV, DF) at one end and kiddies (CBeebies, CCL) at the other.They really have neglected the family centre ground and building an integrated park (Thirteen failed in this respect due to marketing and theme). Frankly I would rather a park with fewer rides and an attempt at some immersion through better theming than one crammed with coasters in whatever space they can get planning permission.
There are unused areas of the park, but those that do have the above are impractical for use for a myriad of other reasons - Coaster Corner being the prime example, of course.
I don't necessarily think this is completely true. I think that they are just hesitant to think outside the box and be a bit more innovative (can't say I blame them too much after the pain of Thirteen's planning and the messy execution of The Smiler). John Wardley's response to a question about whether the park will have to keep removing rides to accommodate new ones was that Alton Towers still has a lot of unused land which could be utilised. I don't think he would just say that if he didn't believe some of those areas were workable.
In the case of the famed 'cross valley' coaster, you only really have the options of Forbidden Valley and Dark Forest.
You're right between those areas is realistically the only place a woodie could go but it should be a standalone attraction that is independent from those areas. The station should be built behind Dark Forest in a clearing with the ride stretching down into the valley and up behind Air. Cramming half of it into FV would be a logistical nightmare in terms of both space and aesthetic
If anything, Dark Forest is closer to what you describe than Forbidden Valley.
Not really - with Ripsaw and (eventually) The Blade gone it will be the same if not worse as Air and Nemesis will have no commonality theme wise from this year onwards and there is nothing else holding the area together. A third coaster within the area would only worsen this and also create claustrophobia. As crap as it is, at least Dark Forest has some coherence between Rita and Thirteen (greyness!!).
I hope they don't go for a similar but not quite the same flat ride to replace Ripsaw, that doesn't really feel like progress. As has been pointed out more times than I care to remember, Merlin definitely doesn't seem to be a flat ride purchaser and if you look at the economics of a flat ride, there are a lot of reasons for that.
The ride was knackered, not unpopular. Ripsaw v 2.0 floorless would be marketable and a pretty moderate investment. It's pretty obvious its not been removed for future development but because they don't want to keep paying to maintain it. The topspin is still one of the best flats around and there isn't much better that could occupy that footprint in my opinion.
Finally, in terms of areas being "incoherent" - I really think this is something that is over stated by coaster fans, I really don't think "the GP" or my preferred definition "people" really buy into it all that as much as this community thinks they do. I'm not saying that isn't a shame, but I think it's simply a fact of life and Merlin know it.
Only because UK standards of 'theme' parks are so poor that most visitors don't expect anything more than a bunch of rides with some vague attempts at theming. People don't care about '"coherence" in itself, they care about immersion and escapism and that comes through creating a coherent aesthetic. If they don't care then how do you explain the popularity of Disneyland, Universal and Europa Park?