Question one can be solved with
Question two can be solved with
First, let's assign a letter to each transformable sub-section of the grid; in this case I'll simply use $L$ and $R$ to represent the left and right sides respectively. Next, we begin by analyzing the letters available for plausible solutions. These are:
Identified by @Morris' ...
I believe the answer is:
One small problem. This is (I think) 65 bumps...
In terms of how I solved it, I wrote a short python script that displays the wheels and allows you to change them one at a time. It's a simple loop in the text so that you can change the positions relatively quickly (e.g. hitting enter just repeats the previous command). Going through ...
I was able to establish 4, 5 numbers and 17, 19 20 letters to meet your criteria. 
Note: This is my no-computers answer; I'll try again at a later date for a computer powered answer driven by WordsApi and YAWL.
1: Special thanks to @Stiv and @Simon Jenkins for pointing out an additional number and three more letters!