Re: dribbling the ball with top speed
For starters, I'd suggest dribbling out ahead of your body if you're in the open floor at top speed. Keeping that dribble close to your body when attempting to stride out and break away just creates situations where it's much more likely you will lose control of the rock because it's trajectory cannot keep up with your speed. Placing the ball out ahead of your body allows you to sprint and catch up to the ball as you make your way down court.
As with any other part of dribbling, I'd also recommend pounding the rock as hard as you can. The quicker and stronger you can make it come back to you, the more reliable that handle will be. I'd also say be cognizant of when it's speed dribble time and when it's protect dribble time. In flat out foot races, pushing the dribble ahead works. But if it's going to be a matter of weaving, accelerating, crossing, I think 1-on-1 full court dribbling drills could be of assistance.