I wish more owners were as curious and interested in the well-being of their birds as you. I know I flipped out and googled all kinds of feather questions when my Quaker went through his first molt with me - I was certain he was plucking, for how many feathers he was losing on a daily basis.
So many people aren't bothered with these tiny little changes in their bird's condition, and it is such an important habit to have when birds are such stoic creatures that tend to hide illness. It will make it far easier for you to notice the little changes that will help you catch potential illnesses early.
Keep up the good work.