I agree with ReiGun, holy crap Laurel is driving me up the wall. She is "self-righteous and preachy" personified. Her and her dad are just... ugh. They've got pretty terrible writing, which sucks since I'm sure at least Blackthorne could do better than this. I'm not too familiar with that other actress though.
Katie Cassidy isn't normally saddled with goodie-two-shoes character. She normally plays a feisty, snarky character (see: Supernatural, Melrose Place, etc). So it surprised me to see her playing such boring coat hanger here. Such a bad decision to write the character in that way. I don't know if the real Laurel Lance in the comic is such boring character but I'd like to think that's not the case.
Dude. isn't that oliver's sister?
Eww dude, no. His sister never looked like this without the mask on:

Also, they mentioned Blüdhaven on this week's episode. That was interesting if they do indeed go there.