How would I say 'open your eyes' as in 'don't be so naive'? Would 'ouvri je ou' work? And is there an expression for that?

Yes.  These would work:
Ouvè je w.
Louvri je w.
or 
Ouvri je w.

The expressions for that would be:
Mete nanm sou ou.
Kale je w.