Whoa! That's a cool quilt. It sure would be fun to make! I didn't see any errors in the instructions, but I found the beginning a bit confusing. For example, "You can probably cut the yardage down slightly if using a non-directional fabric" isn't very helpful. How much can be cut down? I think if it will usually take 2.25 yds, then leave this part out. Also, I'm not clear on the purpose of including how much "waste" there is. I guess I just expect there to be some leftover fabric for most patterns. You might just say "will be cutting strips into 37" and 39" lengths".
This is just my 2 cents. It's a great pattern and you did a great job!