Okay, I've spent a bit more time playing with BLU healer. What's funny is, every time I go into a party I ask to heal, I am actually enjoying this. Healing wise I agree the cooldown on Angel Whisper needs to be lesser. Maybe one oGCD heal could be added and that's it.
But let's look at running stuff as a BLU healer:
My healing aspect is simple, spam between Pom Cure, Exuviation, White Wind and I don't yet have Gobskin, but that's fine. I also Cactguard. I am on my toes watching people's health because I need to leave enough time for me to cast a spell whilst also react to damage taken. This is engaging from a healing aspect because I am thinking more about my healing than normal. Although there is not a huge variety of healing spells that I can use, I conversely find myself have more of a healer focus than I do on my SCH or AST who have tonnes of healing spells.

But sometimes things are going well. People are together, just like the Sophia party I've just come out of. People were together and I had my moments of downtime.

What I've had is variety. First downtime, I might pop Off-guard and dump my Surpanakha in quick succession and drop an Eruption. In trash pulls, the next might be Whistles, Fazes and Sharpened Knives until stun resistance builds (obviously not effective for bosses) and then I could swap to do Whistle + Drill Cannons. If in an AoE situation, everything I've used on single target except Sharpened Knife is applicable and I can also throw in my Ram's Voice and Dragon's Voice combo. And now that I've got Quasar, it's another oGCD that's not shared with Eruption I can weave. Most of these skills as a healer BLU get weaved, as in most cases I am more compelled to heal damage more than I do on other jobs.

Now the variety I have in my current set up isn't based on "do what I feel like" either, because Surpanakha needs time to build 4 charges, Eruption and Quasar have a recast, mobs build resistance to stun and freeze so those types of attacks become less effective to spam, so I move around what I've got available that's sensible for me to use. I still have plenty of skills to learn, so with time, I'll end up refining a good balance.

Whilst I get people are disappointed with Blue Mage content, but it's this experience here in the dungeons I've got in PF that I've been enjoying and kind of makes me miss the experience I had healing back in 2.0.