TLDR: Not really a fan yet.
Spells:
First bit of confusion. The spell table lists the standard 5/2 level 1 cantrip/1st spell per day. But in the spell description it says we start with 3 1st level spells. Not sure which is the case. The Witch class states 3 spells at lvl 1 as well but shows it in their spell table.
Curses:
I'm not sure if it was a typo or not, but it says if we use the Casting a Spell action while under the effect of our Minor Curse Effect, we progress to the next stage of curse. Was this supposed to say use the Casting a Spell action for our Revelation Spell? If not this turns one of the main class mechanics into something that just feels punishing for the player rather than something they want to interweave into their gameplay.
Mysteries:
Battle: Seems pretty balanced. Compared to the other Mysteries though, there is A LOT less detrimental effects to the Oracle herself. Although I don't see myself casting the Revelation spells. Zeal spell just seems more potent.
Flame: I don't know why anyone would take this curse. All of these terrible things just for some increased Reflex saves seems pointless. I also don't understand why you become concealed from others at the Moderate Curse level. The fires are still illusionary then, how is it effecting other's interaction with you? The Major Curse effect just isn't worth entering into. MAYBE if it were 2d6+CHA fire damage aura, and you take CHA fire damage... I could see that. Keeps the theme, but doesn't completely cripple you.
Life: This I feel has a good mix of risk/reward added to it.
Feats:
Divine Element: This would be a good feat to take... if you could see past 30 feet. I don't know anyone who would cast Fireball or Meteor Swarm with a vision range of only 30 feet.
Greater Revelation: I assume when it says "... if you have Advanced Mystery feat..." it means Advanced Revelation feat.
Paradoxical Mystery: This just doesn't seem to have the same power level as the other two feats.