Actually you bring up a couple of really good points that I want to reiterate. (Idk why I didn't think of them myself tbh). DPS/Damage done and HPS/Healing done are two completely different beasts when it comes to WoL. For the most part Damage done is pretty straight forward, early on if you did a lot of damage you probably did a pretty damn good job on that particular fight just in general. However in healing, if the raid avoids damage then there's nothing to heal, and if there's nothing to heal it doesn't mean that you did any worse or any better than a #1 ranked healer in world of logs. All that means is that the number 1 ranked healer was heal more damage, that could mean that he/she either solo healed a fight that's normally two or three healed, or that the raid simply took more damage and forced that healer to put out more than if the other raid didn't.
Also, all of the fights (every single last one of them) in MGV and the ones that I've seen in HoF are all predictable damage. There's no "I need NOW" random bursts in either raid that I know of. If you're leaving it to the last minute to generate chi and not planning ahead as a minute then you're doing it wrong. Being a healer doesn't mean acting on impulse and reacting to events to keep people alive, being a healer is all about planning ahead and predicting damage, and knowing what you're going to do 5 steps ahead. It's a lot like chess actually, if you're playing it move by move you're probably going to lose, but if you can look ahead and plan your moves accordingly then you're more than likely going to win. Don't let the game play you, play the game, manipulate it and manipulate your opponent into your own plan. Same goes for healing.