I've been told mostly that yellow is fine, but DARK yellow is a sign of dehydration, with clear being over hydration. My personal comfort level is around 64 oz, at a guess. I drink a 27 oz bottle of water at work, with a few glasses at home in the morning & evening, as needed to take supplements.
I don't know about mineral balances. I do know you can flush your system too much, but I feel like you'd have to be obsessive or go really overboard to manage that. Drinking a lot of water is just not comfortable. No more than 64 oz is good for me to go maybe around times a day (never getting to a point of "need to go now!").