That's actually not true.
The only time you can spam Chain Heal endlessly is if it is hitting multiple targets, and you get a really nice run of luck. But if your other targets are, effectively, covered, you're wasting your time. What's more, the cast time coupled with the low amount that it actually heals (it has been nerfed fairly significantly from what I am seeing on live right now) makes it a poor choice for a tank healing spell at present. If you are offhealing the tank, then sure - Chain Heal mindlessly away to your heart's content. But if you are the main one responsible for keeping your tank up through the inhales, then you need to be using another spell.
What "Chain heal buff" are you talking about, anyway?
The Chain heal buff I'm talking about is the one where if you cast it now with full effectiveness, it does more total healing than pre-patch. The evened out drop off healing strengthened it on multiple targets, not weakened it. If you have 1 target to worry about and only 1, I absolutely agree, it's worse.
However, you simply will NOT run out of mana in current content as a Resto Shaman spamming Chain heal non-stop if it manages to jump the full set of jumps every cast. On Festergut, it does
do that. There's no arguing that. Even at 3 stacks of Inhale, your entire set of melee (raid, even) is taking a small amount of damage every 2 seconds. 99% is low enough for Chain Heal to jump, and your other healers are not topping people up to 100% in that two seconds every time. You don't need a run of luck to not run out.
That's not true at all. While the Shaman may be casting near constantly, if the raid isn't overfull on healers, he's generally going to have very low overheal - because Chain Heal is a smart cast. It's automatically going to be jumping to targets that most need it, thus making it a supremely efficient spell. This is my point - if he's far exceeding the median for overhealing, then that's an indication that there are too many healers in the raid. The reason I bring this up is that the OP says she feels like she's "three healing" the encounters, and the meters are showing the Shaman to be low - but that's what's going to happen if there are too many healers in the raid.
Just because Chain Heal jumps to the lowest targets in range, doesn't mean it's doing it effectively. Chain Heal can and will jump out to the close ranged raiders, and then even further out, missing a chance to heal a decent target back in melee. There are also some encounters where you have less than half of the fight that needs the full number of healers, where the rest of it may only need 1 or 2. The start of Deathbringer Saurfang and most of Marrowgar come to mind as dead-times where you can't just drop healers.
I don't think I agree with that. We always bring two paladins with us on our encounters, to tank heal and help with some raid damage (with their new spells). When we lose a paladin, it shows - tank death almost inevitably follows, I know that as the offtank healer, I notice the tanks' health become spikey almost immediately.
The top heal for our paladins? Holy Light and Holy Shock.
With how little Holy Light heals compared to Divine Light and Flash of Light, and how slow it is now, if Holy Light is one of your Paladin's top two heals, he needs to be spending more of his mana. Holy Light is free and slow, and is your go-to spell if you pretty much run out of mana and need to keep healing people. You can weave it in, especially with procs, but for it to be a main-casted spell is extremely flawed.
Also, you may need to take a closer look at your healing team if your tanks are dying as soon as a Paladin or two goes down. Paladins are good at and used to tank healing, but your raid healers also need to keep a strong eye on tanks and whether the tank healers are in a position to do so.
I don't think I fully agree with this. They're a bit more confusing, because there are things that simply cannot be competed with at the moment. However, as a judge of damage being taken, where your healers are in relation to each other healing wise, if people are simply not casting, things like that....meters are perfect. Even now.
I said in a sense of healing amount = skillful contribution. There are many factors involved in reading a healing meter and assuming all of those factors are exactly even, the Druid and Disc Priest are simply healing more effectively. :(
PS: What use are nested quotes if I can't fit all of them into one post? :p