Henry
Autoexreginated
You may want to check out the Interplanetary Teleport thread on the Paizo boards. It started when the new campaign setting came out.
The weird thing is, I was pretty sure James Jaccobs had stated in that thread that the spell was in the Golarion book, and wouldn't be in Ultimate Magic because that particular restriction was specific to official campaign settings. For that reason, I was surprised to see it in Ultimate Magic.
Easy enough to just ignore if you prefer PCs having access to multiple planets when they would have access to 7th level spells instead of 9th. I think for me it would largely depend on the kind of campaign I was running.
Oh, I would think that part was easy enough:
If you attempt to teleport with insufficient information (or with misleading information), you disappear and simply reappear in your original location.
If they think the moon is made of green cheese because "they read it in a book somewhere" (due to metagame info), and it really isn't, then the spell fails. I've never been one for making new rules where there doesn't need to be. However, to each his own - I've never had to be responsible for a bunch of RPGA-types trying to actively break rules, either.