Thank you so much for the feedback! I am happy to help out however I can, so don't feel bad about any questions at all.
You are correct that saves are meant to be rolled on or under ability scores. For players who prefer for high rolls to always be better than low rolls, you can instead add the ability score to the die roll, and try to roll 21+ (with a roll of 20 always meaning success, and a roll of 1 always meaning failure). It requires a little more arithmetic in your head, but the odds end up being exactly the same.
Saves are based solely on characters' abilities. In easier situations, consider skipping a roll entirely, or providing more favorable results on success; in more difficult situations, consider greater risks on failure. Check out this post on "Difficulty in Bastionland" by Chris McDowall, whose game Agents of the O.D.D. is based on, for some terrific suggestions.
And yes, if you ever find yourself struggling to remember any rules, I completely endorse simplifying things however works best for you. Honestly, I do it pretty often myself. I'm hoping to give some better guidance for this in the revised edition I'm working on. Thank you again!