I never brought myself to watch the anime, since I really like the Visual Novel. Going from your description I might end up watching this movie sooner or later though, since it used many of the VN's good points. Sakuya not really being a part of the movie's story also is nice, since I really hated her...
The story having so many plotholes is not a problem too, since I know it from the VN. Also, if you liked this you should consider giving the VN a try, it's really awesome. And Princess Waltz too, the fights in there are probably even more awesome.