I plan to max Mnd in the first instance, ignoring all other stats until max.

DPS is irrelevant.

Can people that heal groups a lot share what stats they use? Info about healing the higher level dungeons would be most useful.

I'm not a healer but the one I know probably has max Mnd. Staff damage skills aren't as bad as you would think- Chase Blister pierces enemies in the way of it's target, Holy Pillar is nice AoE, Holy Light is nice single target. And since pure Mnd gives the most healing potential, I'm assuming they all go max Mnd (and some Wis at some point since it reduced mana costs for Staff).

If you're asking about skills it's just Idaten's Grace / the speed Ougi, Cure for healing things while fighting, Heal for saving HP pots, Invigorate for skill spammers, Energy Ball for self healing, and a spare Resurrection staff in case someone dies. Can't say much about how to use them, other than using tab.

MND is most important but WIS will probably be really useful for it's sp cost reduction and regen improvement. DEX is probably worth it later on as well as cooldowns can be crippling when your party members are taking damage a lot.

Dumping every point I get into MND as I level has been the best way for me to get better heals fast.

I do not struggle to heal players way above my level.

I agree that the DPS from staff skills is also decent using the above.