To answer your questions:
1) yes the data can be collected, actually any wirelesscard recieves packages that doesn't meant to be recieved by that card all the time. Normally the card discards these packages, but with some software you can save these.The packages are encrypted by the router (there are 2 kinds of encryptions WEP/WPA(2)) so no-one can do anything with it untill you crack the password.
I will not go explaining to you how to crack them, but use google if you want to know.
2)WPA2-psk stands for WPA2-pre shared key, so the key for the network is shared before any other packages are send (google 4-way handshake). This is the most secure encryption a router got, but you should still use a proper password when using it
If you have any more questions, just ask
sorry for the lack of details, but I have to go to work