White Mage absolutes?

[PArcher]

You don't need it. I killed Twin for the first time without it (or rather with it but I forgot to use it, because I'm super good at using my CDs). You can get by without it, particularly if you have a SCH and SMN in your party.

That said, might as well - once you hit 30 and do the sch quest healer queues are pretty quick, and while it might not be NECESSARY, it certainly can help - it's great during snakes and while it's not enough to skip a set of tank cooldowns on death sentence, it gives you a little more buffer in case Twin gets a high DS or somebody misses a shield.

Technically...you don't need Swiftcast either; you should be able to complete any content without it

But...why wouldn't you grab it to have just in case?

Mitigation is mitigation; less damage to the tank is less you have to heal and less you have to worry. And if you have a SMN SCH and BLM in your party...you should be able to rotate E4E pretty well and get insane uptime on it (don't nerf this SE like Virus please)