Ok well nothing jumps out as being seriously wrong in your xml. Your Steps per unit seem a bit low but that will depend on your setup etc so could be correct.
You definitely do not want to use a kernel speed that you do not require so dont go above 35KHz unless you need more due to the steps per/velocity you need.
Have you run the DriverTest to see if you are getting a decent pulse?
What kind of motors, drive, reduction, ballscrews etc do you have?
Hood