No problem, we all have ‘other projects’ that infringe on our pattern making time 
Yes, that’s correct. The idea is to get used to using references inside of the pattern (this makes the pattern resize smoothly when the measurements file is changed) and to keep the 180° angle on either side of a point - often these will be at 90° to something else, but this isn’t a hard & fast rule in this type of curve, so you can adjust them in small increments until you get the desired curve.
I found it much easier to be able to edit the points rather than to have to open the Properties of a curve each time I wanted to make a minor adjustment.
Yip! first you lay the game board & then you play the game. If you wish, you can delete the curve (you can always Undo the delete, or download the test file again) on the file that I sent you & see the points that I lay down before creating the curve.
The method is described in this topic, which could help you a lot to decide on the length & angle of you curve control points, won’t really work in your case, however, this can be solved if you don’t expect to change the size of the pattern.
I’ve added a new curve to this test file which you can have a look at:
Curve Example - B.sm2d (6.9 KB)