re: doing away with rank
When I first began reading about Aikido, I liked that there was no rank or at least no colored belts, before black belt. This to me put the importance on learning the art, not achieving new and interesting colors for your gui wardrobe. Now as a member of Clark Sensei's Jiyushinkai Aikibudo at the Aikibudo Dojo in Lewisville, Tx, I can see both sides. I could do without the belts, but admit to a feeling of accomplishment. On the negative, Aikido is a communal art, and belts can segregate.
However, I do believe Dan rankings should continue. There is quite a difference between a Sensei and a Shodan, and that should be denoted.
Those are the thoughts of a newly promoted 6th Kyu (not very impressive, eh)