Hint 1
Hint 2
Hint 3
Hint 4
You got most of them from the safe in Zoe's room originally, remember?
How do I find and open Zoe's safe?
When your room is ransacked, the cards are taken --
My room has been ransacked!
-- but you'll get them back when you confront Alec with the evidence you found in your room (i.e., the laser on the window ledge).
What do I do with Alec's letter?
As for the ace, the key to that is in Kate's music.
How do I get a copy of Mom's music?