I was looking to add an argument that allowed you to increase/decrease your velocity by a specified amount, but got as far as trying to understand the code before realizing it's years beyond my experience. So now I open up the idea to anybody else who might be able to accomplish it (or even better, assist me in the feat).

Examples:
"cruise +5" would increase your current velocity by 5 m\s
"cruise -10 forward" would decrease ONLY your forward velocity by 10 m\s

If the increment were to move your velocity passed a 0 (e.g. if you were traveling at 5 m/s and ran "cruise -10"), then you would change direction (following the example, your new desiredSpeed would be 5 m\s in the opposite direction).

Thanks for any help.