Self-explanitory...I just need an extra elective to take but most of those first year courses either don't interest me/are full.

Usually not, but check the prereqs. If there's no prereqs, you should be allowed to take it. Otherwise, it will say "Open to Level II students and above".
Chances are, the second year courses will be full too though, because the class sizes tend to be a bit smaller.

Most of the time yes. I would strongly recommend it as it gives you an idea what upper year classes are like and puts you ahead of the game!

yes
as long as you have the prerequisite course

Originally Posted by djRAIN

yes
as long as you have the prerequisite course

this is the correct answer