Simple question but can find a good answer.
Is a Life oracle with Energy Body active a solid or incorporeal?
The "being of pure energy" "like a fire elemental" and "pass through a living ally's space" is sending mixed messages.
Undead seem to be able to damage the oracle (and take damage themselves with natural weapons or non-reach weapons), but then it makes a mere mention of "creatures" with reach weapons not taking damage, implying that non-undead creatures are also at risk?
We've been playing it as fully incorporeal, but after re-reading the rules, I'm not so sure anymore.
Is a Life oracle with Energy Body active a solid or incorporeal?
Solid/corporeal.
The "being of pure energy" "like a fire elemental"
As far as I know all elementals are corporeal, unless it specifically says they are incorporeal. If you look at the elemental creature template, it doesn't mention them as being incorporeal.
"pass through a living ally's space" is sending mixed messages.
Anybody can always move through an allies space whether they are corporeal or not.
Undead seem to be able to damage the oracle (and take damage themselves with natural weapons or non-reach weapons), but then it makes a mere mention of "creatures" with reach weapons not taking damage, implying that non-undead creatures are also at risk?
We've been playing it as fully incorporeal, but after re-reading the rules, I'm not so sure anymore.
I believe "creatures" is just a poor choice of words, since the previous sentence only mentions undead taking damage, and your flames give off pure life energy which only harms the undead.
Just to confirm the correct answers others have given:
The opposite of incorporeal isn't solid. Liquid water is corporeal, for example. Elementals are corporeal--even if they're pure energy, they are corporeal energy.
And it damages any creature harmed by positive energy, which is generally only undead, but certain races (Dhampir), items, and builds can flip that (I think Bone's Oracles?).