That layout can't be accurate because there should be at least two areas where the track moves around about 300 degrees of a perfect circle for the scenes with the dome screens. One of those would be the Quidditch scene (or as this "layout" calls it,"Flying Game?").
I don't think it would be quite as messy as one might think, since a lot of the twists and turns are generated not so much from the track layout, but from the movements provided by the Kuka arms, which keep the vehicles several feet above the actual track. In fact, for most of the ride you are either riding sideways(either facing right or left), or on your back. All those changes in your position originate from the Kuka arms. In fact, there are videos on YouTube (I'll try and post a link), where the ride has broken down, and they have to cycle all the vehicles through, with the lights on, and with the vehicles in a "neutral" position, just facing forwards. The ride of course then becomes pretty tame.
---------- Post added 11-11-2012 at 11:18 PM ----------
Good point. I wasn't really think of the technology that is used on the ride, but you're absolutely correct.
I knew about the "vehicles", however as I wrote that post I didn't think of how the machine itself would be moving smoothly, but the "arms" itself would be the ones moving you up, down, side to side, and all around. The only thing that it doesn't do is go upside down. So therefore, if it does so 360 degrees for example it would still be going down that path since it would be arms doing the movement for you.
The same technology for this ride is also used at EPCOT for the roller coaster simulators Innovations.