I agree. Some of these might be more important or beneficial than others, depending on what you're trying to accomplish, but none of them are a waste of time. In reflecting on myself, I would say the thing I've done that comes closest to being a waste of time has been spending extended periods of time trying out different mouthpieces or reeds even after I already had a set up that worked well for me. But I think it's fun to try out different stuff, so even that is not a total waste (IMO).None of these are a waste of time. You have to prioritize depending on how much time and what your needs are but I see benefits to all of these things.