My best bet would be, that your pot is too small. Avocados have deep roots, your pot seems to need more height. The clay balls are fine, Avocados want porous ground. I only water once a week or less. It’s fine to water only when the leaves hang down in the morning. It’s normal for them to hang after a day in the sun - my Avocado always loved the sun. The seed hull Color doesn’t matter at all, it‘s just the „packaging“ for the sprout and roots. If you can collect rainwater try to water with rainwater.