Thorpe's almost too far gone for me! there's so much I'd want to scrap and start again lol! So much of it isn't my taste anymore. Thematically and stylistically I'd go for something between Toverland and Hansa Park, and re-instate a more Nautical aesthetic
Remodel and extend Rhumba Rapids - using some of land/lakeland area behind it towards the old treasure island site - It would be super themed and include a drop - and would be the first rapids in the Uk to feature a drop, think infinity falls at Seaworld - but engineered to be not so wet for this British climate!
Scrap tidalwave and build a PULSAR (Walibi Belgium) clone in its place with an old victorian waterworks steampunk/industrial theme. Retheme Stealth to a steampunk, rocket/teslar theme
Get rid of the 4D theatre and install a themed funhouse in its building aka Hotel Tartuf/Fiasco
Scrap Colossus, walking dead, DBGT and storm surge, samurai, detonator, Angry birds land, jungle escape, Quantum etc etc.
Replace Colossus with a new-gen Vekoma such as Lech coaster!
Re-theme the old Canada Creek area to 'Sherwood forest' re-open loggers leap, create a medieval village, re-theme SAW to a castles and turrets/torture Chamber theme like Fluch Von Novgorod at Hansa Park, also install a next gen steeplechase coaster themed to jousting, as well as a high ropes course themed to Robin hoods hideout etc.
Re-theme Swarm to 'dragon-fly' with a huge thatched station - with a much more 'natural' and whimsical themed area, taking inspiration from Toverlands 'Avalon' area and taking advantage of the lakeside setting!
Build an out-and-back B&M hyper-coaster that extends over the bridge and along the the side of the car-park skirting the lake and back - in a similar way Silver star does
Build an RMC at some point!
Finally build that hotel on the lakes edge where the old cement works used to be including a waterpark similar to Plopsaqua