1.) There is no such thing as a dumb question; you will never learn unless you ask.
2.) The yellowing of the leaves is a perfectly normal thing, which is semi-predictable; usually the side leaves go first, and the top leaves stay a year or more longer, but sometimes the plant doesn't follow those rules.
3.) The Sharry Baby generally prefers more water, because as you seen, the roots are fine. Your plant didn't show any real signs of under-watering, which is a good sign. The best way to see if you are under-watering is to see if any new leaf growth pleats.
4.) Yes, with a more water retentive mix, you will need to water less. I think you should wait until the mix is almost completely dry to water again, which I cannot say how many days since I do not know your growing conditions, and the time will vary on the season.
5.) You have a very healthy looking plant on your hands, so you must be doing it right! Good job!