What are appropriate questions for each Elemental Plane?
Things... having to do with that element? If you ask a question about Fire of the Plane of Elemental Fire, there’s a pretty good chance of getting someone who knows the answer. Questions about elementals and other creatures (e.g. genies) native to that plane are also definitely appropriate, as well as questions about places on that plane. Also questions about elemental magic (particularly spells with the corresponding descriptor), history of the Inner Planes, and so on.
It’s pretty much up to the DM, but there really shouldn’t be anything terribly surprising.
If you wear items that boost your stats they still work, right?
Uuuh. Very unclear. The text says “falls to 8,” which is pretty absolute and unqualified. If you were wearing a Headband of Intelligence +2, and that happened, you should have 8 Int afterwards – which means you drop to 6 if you take the headband off.
This is a bit over-harsh and also kind of dumb. Talk to your DM.
Items put on afterward would definitely work.
But it doesn't overcome loss of arcane spellcasting, right?
Correct. That’s a separate effect, not a function of the lost ability scores.
Can this effect be healed?
The “fall” in your ability scores is not specifically ability burn, damage, or drain, but luckily greater restoration has a nice catch-all: “Greater restoration also dispels all magical effects penalizing the creature’s abilities.”
As for the loss of spellcasting, the only thing I can think of is iron heart surge from Tome of Battle, which would be marginally difficult (a pair of feats and a minimum of 12th level) for spellcaster to get. Iron heart surge ends all “conditions and effects” on you, which is absurdly vague and apparently (according to Customer Service) covers an enormous array of things. Definitely talk to your DM before using iron heart surge.
Can you “take 10” on this Int check?
Probably, but your DM has a lot of leeway, even without houseruling. The requirement for taking 10 is that you cannot be stressed or distracted: that usually means combat going on around you or you being in vigorous motion at the time, but a DM could easily argue that contacting creatures from another plane of existence, who aren’t thrilled to be hearing from you, at the risk of a hefty blow to your Int and Cha and the loss of your spellcasting, is a pretty stressful situation.
Talk to your DM first.
This check seems biased against Sorcerers.
Like so many other things are. Sorcerers are just simply worse off than Wizards in nearly every department except lying. See planar binding et al. for a major exception, though.
Is there any FAQ/errata to make it an Int or Cha check instead?
There is not.
