Edit: might've been answered fine already, oops!


-1 Prepare a benefic right away (time it so you heal just as the tank buster heals), top it off with a regen if you need to, or use your cd heal (follow up with regen or benefic as necessary)


-2 Collective unconscious casts a barrier + regen on top of you and your friends, so it’s good to use during instances when people huddle up for an ultimate move type deal. I almost never use it in a regulate dungeon.


-3 For cards, you’ve pretty much got the right idea, but it’s a bit simplified.
I tend to like to do royal roads. So, I will royal road a balance or a bole if the party doesn’t necessarily need it for enhanced effects. If I get an arrow or a balance or a bole (depends on the situation), I cast the arrow either on a melee DPS or a castor DPS depending on the situation (if it’s one boss, I usually cast it on a melee first, if it’s a big trash pull, then usually a castor like BLM), but I also like to alternate so everyone gets “turns.” XD Balance I use for DPS as well. If a tank is having a hard time aggroing, I might give them the balance instead in hopes that hitting harder = aggroing (like DRK), but I’m not sure if that’s actually “correct.”


I will RR ewer and spire for an AOE buff (which you get). So, if I RR either of those and I get another card like Bole and I know there is a hard hitting aoe coming up (like within the next 30s or so), I’ll use an aoe bole to give everyone bole. In other cirumstances, aoe spear, aoe balance, aoe spire (if most members are TP based and are struggling with TP), etc. I find that WAR usually could use spire whenever I run with them, and PLD can often use it, too, but not always (sometimes they could use an ewer because flash and whatnot, but I don’t think I’ve ever actually cast an ewer on a PLD /thinks. Never use Ewer on DRKs. It doesn’t typically work because of one of their stances)


Spear and Arrow give addition time when RR and this RR is one I rarely use because I usually have dilation, but it can be especially nice in junction with ewer or spire, though I’ll use it with other cards as well.


Basically, the cards require you to adapt. Make sure you keep drawing and keep using them, don’t hold onto your cards for 5 minutes+ at a time. Try not to keep any card in reserve for a while, even if it’s an ewer. Part of your MP management is not just using your assets like ewer, but it’s also pausing from casting spells when you need to and when you can afford to to replenish your MP. So, you don’t necessarily need Ewer. Use it in the moment if you get it and need it, don’t hold onto it for long.
When you get into the 60’s/70, there will be additional factors to think about for your cards, but you’ll get the hang of it by then.