Few things I'd debate and they depend on party composition.
If you have two healers and one is a WHM, suggest that the WHM uses cleric stance for the first phase. Damage taken by the tank is very low during this phase and the only other damage comes from friction. One healer is enough for this but holy spam helps kill the razor plumes quickly.
Killing Suparna first can be beneficial, despite Garuda's HP gain, with tanks that do not know how to manage CDs properly and a party full of ranged only. Sine you are all ranged, you do not need to worry about melee being double whicked. If your tank has a moderate amount of HP and knows how to time CDs, this won't be necessary though. However, even if you do have a melee or two, a viable strategy can be have the melee and OT go to Chirada while the ranged focus down Suparna. This works well with 3 ranged and 1 melee. So you basically split DPS. Another tactic is to just have a melee-heavy party separate Chiarda while the OT takes Suparna. You form a triangle and just burn her like this. It's effective but very uncommon outside of JP datacenters.
You need to stress the fact that avoiding windburn from the rain she casts is crucial. I see no mention of it in your phase 3 section. You will quickly OOM your healer if they have to cast leeches/esuna on 6 different party members that were hit by it.
Make mention of what actually happens in phase 4. On this part, you should always kill Chirada first since the melee are going to be double whicked if they stack with the MT and Garuda/Suparna.
I would mention that the OT probably needs to be very watchful of who the spiny goes to. It's OK if it goes to a healer or DPS just as long as he is watching the stacks. Provoking it as soon as you see 2 stacks on the member with spiny is key.
It's worth mentioning that every time Garuda disappears after phase 1, she will use rain that causes windburn and this usually occurs right where you kill the sipny plume for the shield. So telling everyone to back off for a while is a good idea.
Another important note as healer: the first reckoning in phase 2 should do little to no damage if 7-9 pillars are up. If not, the healers will need to put up some AoE heals but nothing too big. The aerial blast in phase 3 does no damage as well if everyone is inside the dome. If not, you risk dying (but may survive). The final AoE does the most AoE damage where the healers will need to expend the most mana/cooldowns. If the spiny is killed early in any of these phases, tank LB2/3 can sometimes be used to avoid death.
Overall, a very good guide with the basic template of the fight.
Edited, Mar 7th 2014 1:19am by HitomeOfBismarck