What you are describing is, I think, the same issue I am having. I have done much research into this and spoken to Honda about it and have been told it's normal. I have driven 2 other Jazz CVTs and they both did it to a greater or lesser extent.
Basically, the torque converter in the CVT has a slightly different role than other automatics. Basically it is there just to get the car rolling. This is where most clutch wear occurs. At about 15mph, a lock up clutch engages. When accelerating, you'll notice the revs drop slightly at this speed - it feels like a normal auto changing gear. It's the lockup clutch engaging and taking out the inefficiency of the torque converter - the differential between the drive and driven side. The jerk you feel when slowing down at about 8 mph is the clutch disengaging because the other parameters for it disengaging at a higher speed have not been met. Lock up clutches on traditional automatics engage/disengage at higher speeds. Unfortunately, in this cvt the lockup clutch is sometimes engaged at lower speeds. If you stab the throttle at low speeds, it will suddenly disengage and cause a jerk. Sometimes if you accelerate and then quickly release the throttle, it remains locked up for a second and then releases which causes a jerk. I seem to be the only person who has driven my car that has noticed this. I also don't notice when a passenger. Mine is due a fuid change so this may help a bit.
I have managed to adjust my driving to limit this. Gradual press or release of the accelerator (rather than a prod) helps. In traffic, putting it into S mode also helps.
The jerk when you release the brake and accelerate from stop is caused by the rollers engaging the steel belt. It depends how hard you press the brake at a standstill. If pressed hard, the steel belt will be released, effectively putting the car in neutral. Release the break and it will need to engage the steel belt. If you press the accelerator before this is complete it will cause a jerk. The best way to avoid this is lighter pressure on the brake at a standstill so it doesn't release the belt, release the brake slowly or release the brake and wait a second or two.
Hope that answers the question!