We need to know what your stats and build is. Do you get into combat and whack enemies? Do you stand away and cast and heal? Do you get up close and tap enemies in bad places with bad spells?
When I play Clerics I tend to dump Strength, so getting Weapon Finesse could be handy for making those touch-attacks hit.
That said, your domain touch attacks suck so possibly not necessary.
It looks like you are focused on channeling to some extent so I would go with Improved Channel.
Extra Channel, perhaps, given that you seem to be going the channelling route.
As a cleric, I also like Extend Spell because you have so many long-duration buffs that would benefit from it. Reach Spell is handy for using your touch spells at longer range.
Scribe Scroll is very handy for leveraging your enormous spell selection -- make scrolls of those once-in-a-blue-moon spells so you can always have them available when needed.
I have be ER regretted taking save-boosting feats as a cleric -- yes, you have good Fort/Will saves and high Wis/Con, but Iron Will and Great Fortitude are never wasted.
Improved Initiative and Combat Casting are never bad feats for spellcasters.
Quick Channel.
Possibly preceded by Extra Channel.
Dodge
Or shield focus. Follow up with the delfect an arrow with a shield feat.
Cannot hurt to up your ac. And its always nice to negate an ranged attack.
Leadership.
Have the following
Toughness
Selective Channeling
Versatile ChannelerWhat else is there that could be useful to a Cleric with the Death and Healing Domains? Playing a PFS Cleric of Pharasma.
Which one have I missed that might be really useful and why?
Seeing as you have Versatile channeler I would go with Improved Channel. At lvl 8 or 9 and up, many creatures are able to make the save vs the channel instantly halving your damage output.
Bleh, channel focused cleric.
In any case I'd keep with the channeling theme and grab quick channel. Spells are better uses of your actions than channeling so up the efficiency and start doing them as a move action when possible.
After this though seriously start looking into metamagic feats and means of improving your spellcasting. You can get more channels as you boost your charisma while simultaneously bumping the DC so that's not a huge worry.
Extend the range of spells (touch -> short -> medium -> long) at the cost of one level increase for each range increase. Since you can cast cure spells spontaneously, you can use Reach Spell on them (and thus, say, use a 2nd-level slot to extend cure light wounds to a short-range spell instead of a touch-range spell -- or a fourth-level slot to cast it at long range.)
Reach Spell is a good feat. Combat Casting is always useful. Command Undead could be also a good choice, assuming you ran into undead with reasonable frequency. Taking down undead with mulitiple uses of channeled positive energy you could instead use to heal is not as useful as taking control of them with one use of Control Undead, even assuming all you're going to do is turn them against each other.
Leadership.
With profound sadness: Leadership feat remains unavailable as a choice in Pathfinder Society.
