From level 8 to 12 they are actually pretty useful, specially if you are leveling up an alt that you can keep training magic level on the training school for a few weeks. If you hunt monsters that are week to the element, you can level pretty fast by wasting some mana potions (that you would already have from daily reward if you were training). After level 12 they become very useless, but can be used to kill very week monsters that are trapping you, I guess.
The healing spell, tough, I use it all the time: as it is a healing spell, it removes paralyse, so if I have enough HP or if I am using mana shield/energy rings and I am suffering from paralyse I use this spell instead of a more powerful heal to save mana