2) Anywhere that says if I can see a hiden creature's aura with arcane sight.
Since no one has answered this yet:
Hide prevents a person from seeing you, or your equipment. Arcane Sight allows you to sense magical auras. They don't interact.
If a creature has Invisibility on it, and it runs up to you. Say you fail your Spot check but have Greater Arcane Sight active. You don''t see the creature, but you do know that there is a strong illusion aura that just came up to you quickly and is still there. Likely, you also passed your Spellcraft to know what the spell is. So you know there is something, and likely someone, there, but they still have total concealment.
There is no rules quote on this, unless you want someone to quote the effects of
hide,which don't actually say anything other that it is opposed by spot.