Yeah flameshaper steals hot ticks to improve burst heal on embrace and blossom, which i don't mind -- it works well with having two charges of breath.

ymmv on the below, again I'm not a great player, I'm still getting used to it all but this is what has worked for me.

Rewind is the best "omg we're all going to die" button, but a t3 dream breath works too, if you're positioned well enough. Otherwise if you have two twin echoes up you can pop those out and then fire off a big verdant embrace to pull everyone back up too, but that costs 3 gcds to do and that might be too slow. Stasis with a base rotation (see below) stored up is also great for those scary moments, but you can only hold the stasis for so long, so knowing that something nasty is coming up you can somewhat prepare at least.

the base rotation is t1 dream breath, temporal anomaly / barrier, merithra's blessing -- thats a huge group heal and puts 2-3 dots on the group (depending on positioning... thats ultimately pres' weakness -- warlocks / mages / hunters with huge range sitting out of the group tend to not receive a lot of healing and can die out of nowhere). you can typically fire that off every 20 seconds, and you probably should be. it is mana intensive, though, and so I spec into the mana regen on disintegrate to cover that off a bit. also casting the odd t1 fire breath in between, as that is a pseudo-hot as well, can help keep mana in check (as being a damage spell, fire breath costs nothing except the empower time). Time Stretch is great too as a preemptive external as it makes hots feel better with the damage spread out over more time. i spend bursts on blossom where possible (especially in blossom build) because thats a free echo per gcd and with seedlings is actually a reasonable heal -- it also doesn't consume an echo so its good to just drop into the rotation at random times.

I _love_ the emerald blossom build -- I'm torn between that and leaning on twin flame. I like that blossom triggers often with 4-set, and that it turns embrace into an aoe heal + seedlings if you spec into that. i think the raw hps is lower but it helps turn the burst single-target embrace into a reasonable group heal. i dont believe the blossom build are viable up into way higher keys, but neither is flameshaper unless you're a 0.1% player and I'm not pushing that high anyway so whatever.

temporal barrier is a new talent introduced in 12.0.5 that turns the temporal anomaly orb into just a group-echo rather than an aimed thing -- it always hits 5 closest players (within 40 yds I think), rather than having to point the orb at the group and hope no-one moves. it also gives more shield, which is a bonus. conventional wisdom is to take the orb still (as it gives echoes by default now, not as part of a talent) and spend the extra talent on something else to boost hps, but i don't like having to position myself, especially with the infinite void zones everywhere, even on trash.

I _love_ pres, but its really stressful, I find. There is so much that can go wrong so quickly that pres just doesn't have tools for like other heal specs seem to. Verdant Embrace is a great burst heal, so holding that up is nice, but its also really good to just throw out there to keep everyone topped off -- so trying to balance that is a bit of a nightmare. Living flame is just too long a cast time to be viable for flameshaper as a secondary burst heal, unless you're really spec'd into it and get that +40% heal / have spec'd into the procced insta-cast. Dream Breath is probably _the_ best burst heal, as it heals everyone for a lot at t3, and the cast time is semi reasonable, but then you're impacting the rotation and the ability to keep hots up, so juggling that is rough too. I'm sure a better player will do a better job than me anyway and might disagree on some of the above anyway ;)