Just a question about how ALL DPS setting handles the Healing Done + spell damage stat. AMR is saying Signet of Aeranas is better than Farseer’s Band. The Signet has less int, less spell power, and doesn’t have spell crit yet it does have mp5. Is this being rated higher because of the mp5? or is the healing done stat on the signet causing it to be rated better and if so, how is healing done being handled for prot paladins?
I need you to post a snapshot to answer your question specifically. There is a link that says “help” above the gear table when you are looking at BiB or BiS on the site. Use that to create a snapshot.
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+Healing has no value in our optimizer for a protection paladin. It looks to me like your character would be mana-limited in the setup you have specified (no raid buffs or mana consumables used), so the mp5 is more valuable than the other stats you would gain on the farseer’s band.
Thats perfect! Thanks Swol 
does it have value for the spell power given by +healing at a rate of 1/3? eg. +99 healing is still +33 spell power, so is that accounted?
+healing does not give +spell power. An item only has spell power if it actually states on the item that it has spell power, and that is taken into account.
While it was like that in Classic, in TBC all +Healing does indeed give some +spell damage (about 1/3 of +Healing).
See e.g. Light’s Justice from Prince Malchezaar:
As far as I know, if an item gives spell damage, it will say that it does as in the tooltip shown above.
Regardless, we parse the actual game data extracted from the client, and it explicitly says which stats the item has. Or in many cases, it is actually a spell effect with an aura, and the aura has data fields that explicitly state which stats the item will have.
If you have any example of an item where it shows that it only gives +healing, but you have verified in game that it actually increases your spell damage too, let me know and I can compare it to the raw game data.