It would be pretty difficult to type out the answers here, but I have experience in both, so I'll do what I can. (note: this is based on MY experience, and what I have discovered)
Q: what did the Gracies add to Japanese JJ?
A: Carlos Gracie was taught Japanese Judo and Jujutsu by Maeda, a judo champion with an unorthodox ground fighting style. Carlos' little brother Helio was very small and weak, and found much of the techniques did not work for him. he used the Japanese JJ methods of leverage, and his own theories that would work for a smaller man. His style would evolve into a ground fighting style using leverage and technique over strength.
Q: Kicks in JJ? BJJ?
A: Kicks (in pure BJJ) are not really focused on. they are used in self-defense/standing techniques to set up other techniques, and in ground sweeps. in Japanese Jujutsu (depending on the style) they are used but not to a large extent. thrusting kicks that bring a person into a certain range is common.
Q: Does it take 9 years to get a black belt?
A: most definitely. There is approximately 88 basic techniques for each belt level. GM Helio Gracie says that he could teach someone all the basics in 40 lessons, bu it takes 10 years to "know" the person's character. BJJ has a feeling that can only be learned by time.
Q: Belts?
A: white, Blue, purple, brown, black. White is the phase where one learns the concepts of leverage, and positioning. Blue to purple is considered the hardest phase. as for time, 1-3 years for blue. 2-4 for purple. 2-4 for brown, and 1-4 for black. depending on your skill, and who your teacher is.
The thing to recognize, is the difference between the various schools and styles. each has there own strengths and weaknesses. for example:
Gracie Jiu jitsu - This is the school that trains directly under GM helio Gracie. Rickson gracie, Royce, and Pedro Sauer to name a few. this style focuses on leverage, and application of self defense techniques.
Brazilian Jiu Jitsu - a common name given to the art, BJJ refers mostly to the sport, as used for mma and competitions. some practitioners of this style combine wrestling or other styles, along with strength with Jiujitsu. Joe Morreira, Rigan Machado, and Carlson Gracie are notables.
Luta Livre - basically, this is Jiu jitsu without a gi. Hugo duarte is a notable practitioner of this style.
Bravo Jiu Jitsu - an unorthodox style in, like Luta livre, uses no-gi techniques exclusively. the style is based on under and overhooks. Eddie Bravo invented it, but stylists such as gerald strebendt, Jean jeaques machado, BJ penn, and others.
there are a few styles out there. its best to try a few different linages and find out what suits you best.
