I totally agree with your opinions of the peformances. American Lucy is great, I'd not seen her before! I really don't like Aziza's dancing, her movements are huge and she uses the music in a strange way. I think her performance that won her 'Bellydancer Of The Universe' was awful and the way she butchered Hossam Ramzy's 'Faddah' was shocking.If I am honest, I liked most of all (next to Egyptian Lucy), American Lucys interpretation. She dances a very good Egyptian style. I also liked Orit and Aisha, I found Bozenka acceptable but not great, but I didn't like Azeeza's interpretation. She tries to dance Egyptian, but it looks more like American Cabaret , which is absolutely o.k. for any other kind of music, but nor for Oum Kalsoum (O.k., you know by now that I am a purist, when it comes to Oum Kalsoum).
I agree with Kiraze, that there are Oum Kalsoum songs which are difficult to dance, and others which are less difficult. It depends also at the musical interpretation. If they have been kept "original", or if they have been very adapted to Raqs Sharqi.