Has anyone tried the 51 point talent with all the other shields to get great results in healing?
After I dinged 50 and wearing 6 pcs of wellfare level 50 gear (the rest mostly 48 blues) I can state a few things about this ability. I have both a 51 Puri + 15 Sent build as well as a Warden/Sent build. I use the Puri build for MT healing and the Warden/Sent build for PvP, Experts and Raid healing. Here's what I can say about 51pt Puri:
Spiritual Conflagration's tooltip's stated heal is over the entire channeled duration, not per second, mine heals for a minimum of 2k over 4sec (no buffs), with usually at least 1 tick critting for around 800. The shields ARE 831hp per second and don't seem to stack with other shields and I can say 100% are not effected by Protection of the Ancestors, as for the 831hp shields stacking with each other I cannot confirm 100% that they do, however it's likely the tank will be taking enough damage that at least 2-3 of the shields will see the application. What I cannot say is whether they are effected by the Raid essence that increases Purifier shields by 797. I would say that it's certainly a good heal, but it is GREAT mitigation. Look at it this way, no matter what your per second ticks are you get a free 831hp shield that doesn't cost any mana or GCD to apply.
Would stacking Healing Spray, Rite of the Ancestors, channeling Healing Conflagration on a tank and then spamming healing flame and restorative flame respectively be even viable?
That's a little confusing, but I think to answer the question, you should ALWAYS have Healing Spray ticking on the tank and use ANY shield/heal/channeled ability as appropriate for the situation. Healing is always situational, never a specific rotation.
Is the Purifier tree more of a support heal/shield while in raid situations?
Yes, in a raid setting 51pt Puri would be support on raid or MT healer but usually not both. Puri has too few fast decent sized heals to deal with massive raid damage, plus having only 1 Party heal (passive) which will almost always hit melee and almsot never hit ranged. Theer is one 2sec casted 10ppl heal in Sent if you go 15 Sent with your 51 Puri, but it's kinda meh on throughput. The shields however are perfect for snipe "healing" a raid member that gets into trouble.
DPS: (Inq) 51 (Sent) 10 (Ward) 5
Raid Healer: (Puri) 32 (Sent) 34 (Ward) 0
MT Healer: (Puri) 51 (Sent) 15 (Ward) 0
Tank: (Just) 47 (Sham) 7 (Inq) 12
Inquisicar: (Inq) 51 (Justi) 14 (Sent) 1