Frustrated or not, I can relate to everything you said in your post.
Spanking won't solve your problem...I'm sensing things here that could even be made worse by spanking. And overtired is a possibility, but it sounds like a quick, intelligent mind.
And the yelling? Yup...Last week, during a very frustrating day where she and DS were constantly fighting, whining, she was into everything, telling me no when I would tell her to do something or not to do something. She started playing on the floor next to me and said, "Mommy, I don't like it when you yell at me."
I have such good kids, but when the horns pop out, they are different creatures. And then I become one, too!
I'm not sure about the naps. Diva is so tired at night when daddy gets home and she's so whiny by then if she doesn't get the nap. I'd rather she be rested and fun to be around when he gets home.
I do agree w/your dh about getting him to bed earlier (you need that break, too). Even if he's not tired, he still can lay in bed, talking softly, being read to, etc. I'll bet his body will adjust to the earlier time. I gave Diva melatonin when she was revved up at bedtime, waking at 3am (Dreamerz has some in a chocolate form), and now her body tells her when to sleep and it's so much easier. She now tells me, "Mommy, I'm tired." and will go sit on the bed looking at books if I'm wrapping things up.
We know you love your kids, we know they are great kids. But they are kids....as I type this, my 8 year old is once again being rude to his little sister....she's interfering, putting snakes into his "movie" he's doing of dinosaurs, and he's acting like the temperamental director.