Try making the beginning to the "spiral" more smooth, since you have loads of small stucks now. There's some diffrent strats on how to strafe, mine is to keep left strafe until the spiral. Work on the spiral strafing, I'm not sure what the proper technique is but someone else could probably fill in on that. If you absolutly have to kill guards, make sure it doesn't brake your strafeline. A better boost ratio would also do. Keep at it.