White Mage absolutes?

[Cossette]

What are the absolute must haves for a 50 Whm as far as additional actions go? I know instacast is one but what else and why?

[Anova]

Additional must-haves at endgame are probably eye for an eye and virus.

"Eye for an Eye" (ACN 34) is a good damage mitigation tool that reduces the damage dealt by monsters by 10% for 20 seconds. It helps a healer by reducing the amount of healing they need to cast, thus reducing their overall enmity, and allowing them time to regen mp, lower enmity, or dps. It is very handy when doing speedruns. Keep in mind the ability actually is a buff that applies a debuff to enemies hitting the target with a physical attack. Some bosses like ADS will not trigger the debuff as they never do physical attacks.

"Virus" (ACN 12) reduces enemy STR and DEX, making it easier for your tank to hit enemies (tank generates more enmity) while reducing the damage dealt (healer generates less enmity). Both are very handy tools to prevent overhealing, conserve mp, and reduce enmity. It might see some use in endgame Coil runs (depending on your party composiiton), especially if you throw it on more powerful monsters in T1 and T4.

"Blizzard II" (THM 12) is sometimes handy if you are a WHM solo-ing or leveling up. You bind enemies and continue running to your target destination, or you just put a regen on yourself and aoe. If you're a CNJ, you should have better options.

"Surecast" {THM 8) can be useful when you are working to time large heals to go immediately after a big hit (such as a primal's unavoidable aoe). You might also use it to make sure the stoneskin casts on the tank without interruption in preparation for mountainbuster on titan (immediately after geocrush). It's not necessary, but it is useful and you get it anyway.

[Lemon8or]

Swiftcast because you mentioned it.
Surecast because you might be interrupted mid-cast. Think Titan's Geocrush.
Eye for an Eye to rotate usage on your tank. It's good mitigation.
Virus to use on boss and lower damage.
The last 3 are nice to have just like Swiftcast but it really boosts your ability as WHM.

[Deathgiver]

Eye for an Eye and Virus are both good from arcanist, as any damage reduction no matter how small makes your life easier. They're both off GCD so they don't interrupt your healing at all. From BLM I would make sure you have both Swiftcast (which you mentioned) and Surecast for those times when you need to cast a cure while getting hammered. The other 3 possible cross class skills are lol (Physik - same potency as cure without the freecure procs, Blizzard II - you already have holy for aoe cc and it's way higher potency, and Ruin - use stone II instead), so really not any choices to make. Blizzard II could be useful in very extreme situations where you have multiple mobs on yourself, swiftcast is down, and you need to bind them long enough to let the tank grab aggro.

[Judge_Xero]

I would say a "Must Have" is a great internet connect and good dodging skills.

[Iymala]

Swiftcast and Eye for an Eye should be priority. Virus, with the nerf, is more beneficial if added from a SCH or SMN There are some uses for Surecast (Fireballs from Twin for example), but the first two are major tools in your toolkit.

[Viviza]

There are seven crossclass abilities that WHM can pick up. Ruin is inferior to Stone 2, and Physick is inferior to Cure, so that leaves five choices for five slots.

Question is - are they all worth getting?

Virus you get automatically to meet the lv15 arcanist req.

Bliz 2 and Surecast you get automatically on the way to picking up Swiftcast, which you've already mentioned as essential.

That only leaves Eye for an Eye, which is a solid yet somewhat unpredictable ability. It may proc early, or later, or never, although it usually will. Point is, you can't predict how well it will do its job - Eye paints with a broad brush to reduce encounter damage. You should get it, as there are no better options and it's free in terms of both MP and time, but if you delay a bit it won't hurt you too much.

[Cossette]

Awesome! Thanks for the great responses. I wasn't looking forward to leveling Arcanist but I want to be the best WHM I can so I think I will.

[CompSci88]

I would say a "Must Have" is a great internet connect and good dodging skills.

This.

[Freeheart]

I don't have eye for eye yet I may level up Arc? I think to get it now