Hi Randelph,
I know what you mean about the Part/Mixer being a blur. I've used the keyboard for a while now, and I still get thrown by the way that Part and Mixer do very similar things but navigate completely differently. That part of the UI could really have been much more consistent.
Brad has answered most of your questions well. There's a trick to getting the numeric keys to enter numbers; in most situations where the rotary dial selects a number, you can also enter "0" and then type three digits. For example, to enter "55", you type 0-0-5-5. It took me ages before I discovered that trick, and it really speeds up changing a bunch of numbers from 0 to 127 or vice-versa.