Recovery causes the blind effect on undead monsters only. Used on a player, it would heal their stun/freeze status effects as normal unless they're undead property. Same goes for Cure. The creator you used Recovery on most likely had an Evil Druid card on his/her armor. So no, it's not worth it unless you know somebody has undead armor. Even then, that's what Turn Undead and Magnus Exorcismus are for.

As for the formulas, the Recovery blind effect has a (100 - (MonsterINT/2 + MonsterVIT/3 + MonsterLUK/10)) chance of working, and lasts for 30 * (100 - (MonsterINT + MonsterVIT)/2)/100 seconds.
I don't see the confusion effect being caused by cure in the skill description on the website. This is all I see for Cure:
Cures Blind, Confusion and Silence (limitation: you can't cure yourself from Silence since you can't cast while Silenced).