Of course! We love the kiddos just as much as you do. Bring 'em all with you. This is a family event! Don't feel inclined to though if you just want an excuse for a night off.
Casual. California can be hot already in May. We want everyone to feel comfortable. We're all about to become family, so don't feel like you have to dress up, unless you want to. Bring a pair of flats/sandals if you wear heels for some dancing!