Brownstar
With regards to point b. If you had been speeded by the previous sector for streaming, then came to me and I said standard speeds to you, you would be quite within your rights as far as I am concerned to speed up again or do whatever you wanted until you hit any speed limit points.
If I still needed you on a speed for separation, i would instruct you that accordingly.
Any new clearance cancels a previous clearance unless restrictions are reiterated within the framework of the new clearance (does that make sense? - just been shafted on radar; brain frazzled!).
If you had come across at say 270kts for separation and I wanted to maintain that but to get you to fly standard or normal speed by the SLP I would say maintain 270kts, reduce to 250kts at the SLP. (for example)
If I did not reiterate the maintain 270kts - you could rightly assume that the speed was all yours until the SLP.
Hope this drivel makes sense - I am off to find a dark room
