Let's evaluate two uses of Rite of Equilibrium.
Firstly, playing the second option with a full bless/curse deck can almost guarantee total horror heals. But is it worth the cost? While Horror is a problem in most games, this card seems unreliable if it was the only source of horror heal and normally, the game does not care if you finish with 1 sanity or full sanity so over healing is not necessarily the best use of the card. Choosing this option means you are playing with a blurse deck and this move tends to reset your deck (which is not good)
Secondly, the first option can be used to replenish your bless/curses. As others have mentioned, this can be paid cheaply with Tempt Fate so unless you use Dayana Esperence to squeeze more juice out of this single card, it is normally better to stick with tempt fate (having both to fill bag up faster is an option, but usually there are more things that need to be added to a blurse deck before this one)
Overall this card does not seem playable without Dayana, and if we look at the other spells cards that are 0-cost high xp cost that synergizes with Dayana ( Deny Existence and Recharge), Equilibrium seems to fall short of the other two of the effectiveness though (even Soothing Melody seems to do better)
It could be a niche card to take in Carcossa (or equivalent) campaign with more horror but little damage.
Overall, this card does have a unique effect and can be used in some cases (e.g Agnes Baker to continue her ability) or if there were better rewards for over heal. It might be balanced if the 1st option came with a card draw to at least be on par with Tempt and makes it worthwhile to combo with Dayana, and the second option included damage heal as well (or did not remove the bless/curse)