For the life of me I cannot settle on what I want to do with my Redeemer of Shelyn. I can't decide if I want to go weapon & shield to get shield ally, or go glaive with blade ally, and then after that I can't decide what to do with her feat selection. I mean I want her to be merciful when she can but if a conflict is inevitable (and let's face it, it is) she's able to protect her allies and minimize the harm they come to. But I can't figure out how that would inform the mechanics of this character; it seems a lot of champion feats and features have all manner of ways of protecting others in different ways.
This is a Society character so I can't always guarantee what party she'll be with.
I could use some insight about how certain feat chains affect her role in combat or how feat selections might reflect her philosophy in combat.
This would be a lot easier to answer if we were talking about a liberator. Their reaction could allow an ally to retreat past the reach of an Attack of Opportunity build. That way, you attacks could become the line in the sand.
I think shield might be better for the defense management of a redeemer. You initially have to decide between using your glimpse of redemption and shield warden (Reaction to redirect damage to you instead). But Shield of reckoning lets you combine the two reactions into one.
Admittedly, you have to devote several feats for the shield path, and in comparison, attack of opportunity lets you get an immediate benefit that could end an encounter early by cutting down your enemy's health.
Paladins of Shelyn generally permit a more offensive take on things compared to a Redeemer, since they get free attacks on enemies with their reaction, which would make going more offensive with them (such as using a Reach weapon and taking Fighter dedication with Lunge) ideal.
A Redeemer does not have that component, meaning you will be better served running sword and board, as your ability to actually reach your enemy is irrelevant. Additionally, since your reaction basically automatically makes enemies Enfeebled 2, this means you can further reduce damage you and your allies take, as well as reduce the likelihood of enemies hitting and damaging both you and allies alike, which further supports the "sword and board" paradigm.
So, supposing sword & board (and these are all solid cases in its favor), another major conflict I'm coming up with regarding feat selection is Mercy plus its associated feats, plus a few of the focus spells available.
I've already written off Litany against Wrath since as a Society character I have no guarantee I'll be with good aligned party members that could make it useful, but Litany Against Sloth and Champion's Sacrifice both look pretty sweet, however they conflict with other cool/essential feats. And the mercy feats seem flavorful but again, oftentimes I see a conflict of choice.
(Of course this all is also guesswork on how high the level cap for PFS2 is going to be...)
Sword & Shield works well in PFS because you can tank up when party defenses are low, and you can get extra shield blocks in, maybe take an MCD for versatility. Trouble is, turtling up only helps in some parties and other parties will tend to have poor tactics.
So a Reach weapon makes more sense if you really want to be protecting your allies. That should ensure you can reach the enemy that's bothering at least one ally. It also makes it easier if you need to have a free hand (to catch a ledge, pick up a quest item, drag an ally to safety, not so much for combat directly).
Weight of Guilt is so-so in many campaigns, but such a large amount of PFS bosses cast spells that having the option to Stupefy might be worthwhile.
Deity's Domain is better, see below.
I do not think the Oaths suit PFS (unless it's Year of the Demon or somesuch), so at 2nd I'd recommend an MCD, most likely Cleric for Shield spell, though Sorcerer to branch out into other magic item usage could be good too. Taking more than the first feat doesn't pay off for some time, so I'd avoid that.
One cool thing about Champion is they naturally progress in Divine Proficiency, so you don't need to go MCD to have your Focus Spells advance. For Shelyn, and wanting to protect, Family offers two spells that can be quite useful in PFS. (Her other domains are iffier for Champions.)
I'd get both, have a nice pool of 3 Focus Points (which represents a lot of tanking too) and get the feats to recharge them. I expect PFS scenarios will often have lulls to recharge.
By the time you're higher level, you should have a better sense of whether you have the action economy & desire for Holy Smite (whose main value is triggering a Weakness) or want to load up on auras or whatnot.
Remember, you have an excellent Reaction ability, so further Reaction feats have to be weighed against giving up that usage for their usage.
And pick up speed in any way you can, so Fleet and an early item bonus if you can.