My hot take (which I've said before) is that Gold Coaster needs to go and the entire end of Ocean Parade needs redeveloping from Wipeout to Kevil Hill. That is an enormous amount of land which includes Trolls Village area and Thunderbolt plot, as well as the exhibition centre. It could accommodate waterpark expansion, but given the WWW is closed for half the year, that seems like a poor use of land. The exhibition centre could be replaced with a much better auditorium space built in the redevelopment at the other end of the park which would be more than just a shed - especially if a hotel is planned. This would free up that building for rides/show spaces within the park footprint. I'm fairly agnostic about ride types. But DW's line up is definitely short of a major high-thrill coaster, a small thrill coaster (eg. mad mouse, axis, 4D free-spin), a dark ride and a water ride (which could be combined into one great ride). Flats wise they have a lot of spinning rides, so I'd like to see some more gentle options, like Zamperla Big Wavez or Nebulaz (or both) which aren't very thrilling but are good rides to fill the gap between K&B dreamland and the big thrill rides. They're also visually impressive. I would fix that end of the park first before expanding into Blue Lagoon. It is an eye-sore and a dead-end currently, and the connection between the wet and dry parks needs to be addressed.