little big planet Question

[SpartanFX]

I  have two question guys.

 

when I mess around with the stickers in my pod how can i undo it? (also is there anyway to undo one sticker?)

 

 

next question is for the online community:

 

when you play online,do you collect items/stickers/costumes by playing other people's levels?

 

 

thanks in advance .