I would not say no to Drayton getting rid of G Force and putting Kanonen in its place. Obviously won't happen though even if it ended up at Drayton. Would be a decent addition to almost any UK park really.
There seems to be a thing Liseberg have been doing recently is that there theming their new rides. For example, Helix has got sort of a video game-esque theme, and Mechanica and Aerospin have a theme as well. Lisebergbanana has got a very subtle railway theme (even a little signal that goes up when a train is dispatch which is adorable!), although I think this has always been there. Jukebox, Gasten Ghost Hotel maze, Kallerado all have theming as well.
Hopefully Balder get some theming, considering it's named after something from Norse mythology (Like Valkyria will be), it'll much fit in to the new area perfectly if it does.