It's Goldstriker, not Goldrusher. And they were sort of trying to make a twisted wooden layout. Historically, many wood coasters used to be pretty twisted ages ago, look at Mr. Twister at Elich Gardens back in 1965 or the Crystal Beach Cyclone in 1926, which is legendary for essentially having no straight track at all.
I'm guessing the ride that "goes in a circle like Flash" is the Beserker, aka Bayern Kurve. It's only one of two left in the USA--the other being at Knobels, and is frankly run much, much better (and faster) out there. That said, I'd even take that slower version of the ride just for preservation purposes. It's one of the rides I'm really worried about their fate with the possible closing of the park. The others are the Centerfuge (aka Calypso) and Orbiter (Enterprise), all of which are flat rides that are becoming increasingly rare.
As for rapids rides, you'd actually be surprised that in most of the rest of the country, I'd only say maybe 1/2 have any theming at all, and even the few that do have theming are generally fairly sparse. That's not unusual. Same goes for water flume rides... most are just a trough stilling on supports, not much different than a carnival flume ride. We just happen to be lucky in SoCal to have amazingly themed flume and water rides, but it's really not like that at most parks. I know, I've been to nearly every major park in the country.
While CGA isn't necessarily my favorite park, one thing I do love about it is their landscaping. There's some beautiful greenery around the park if you really look around. That plant tunnel path is the sort of thing you don't see anymore, and speaks to the longevity of the park.
But on the whole, I wouldn't call CGA a theme park. It's more of an amusement park with some theming here and there.