Rogues casting from scrolls

[AuraSeer]

Again, that makes sense. And a Rogue can make a Decipher roll how often? If he fails to decipher a scroll, does he have to wait 1 day, or a level like Wizards do?

One try per day.

In the UMD description, under the 'Decipher a Written Spell' entry, the text says: "This works just like deciphering a written spell with the Spellcraft skill, except that the DC is 5 points higher."

In the Spellcraft description, 'Decipher a written spell' is listed as allowing one try per day. Learning the spell (i.e., understanding it so you can scribe it into a spellbook) is a separate entry, and that's what can only be attempted once per level.