It's quite easy.
Select your object, look at its height, divide that by 2. That's a radius.
Use that number to calculate the circle of your ball (2 *3.14 * radius).
That's the length of the path your ball has to pass from point A to point B to rotate 360 degrees sharp. Just measure it on the X-axis.

I remembered in the fundamental of animation course that we went over the features of Normalize. In this video the issue is when you make a change to the curve it snaps back to the default position of being between 1 and -1 when you normalized it. In the fundamentals video it was shown that this issue could be resolved with turning off a certain feature I believe. My question is whether you recommend using the Normalize feature since this problem is gone, or should I continue with the changing the units from degree to radians like the video showed.

Because of the different scales of the translation and rotation, I find myself matching the start of the animation, then moving to the end of the roll, and finding out that I messed the start or the middle.
After fixing the start curve the end is not accurate again.
I'm doing it over and over, and I'm starting to get scared of changing things (for example I used broken tangents for the wobble so I won't screw up the rolling before that).
Is there a better way to match curves?

This is a difficult but good exercise. After spending hours trying to perfect my spin curve, now I'm looking at the example gif and it looks to me like the ball is spinning way too fast for the movement. It looks like it's spinning out, and is maybe 1.5-2x faster than it should be. I can't not see it now. Arrggh! Is what I'm seeing true, or am I seeing things? :)