time to try some new foods

A snippet of from a reading of a book about animals and the sounds they make:

Q: Who says "Moo"?
Aaron: Cow!

Q: Who says "Peep"?
Aaron: Chicken Nugget!
(Correct Answer: A Chick)

Aaron at 2

Aaron has started speaking a lot. A few months ago I was able to have pretty basic conversations with him. And now all of a sudden he can count to ten. In English and Cantonese/Mandarin (he mixes up the two sometimes).

And he can "sing" a bunch of songs that I never knew he remembered the words to. Like, he can sing "Twinkle Twinkle Little Star" in Mandarin and English. I just barely learned it in Mandarin! And Isaac is still trying to catch up on that front. And he loves to sing "The Wheels on the Bus," but he's constantly asking for variations, like "Mommy! The Wheels on the Tow Truck! Airplane Goes Up and Down!" Some days it seems like I spend the entire day singing a variation of this song to him. He's also become quite bossy:
"Mommy - Sit!"
"Sit HERE! No Couch!"
"Hair DOOOOWN!"
"Turn Around!"
"Mommy! MOMMY! MOOOMMMMMYYYYY! GET UP! NO LIE DOWN!! GET UP!"
"No 'puter, Mommy! No 'puter!"
(You can guess what that last one means...)
I guess when I'm not singing a version of "Wheels on the Bus" I'm reminding him to say "Please."

He's also showing a sense of humor. He tends not to like meat and most proteins, but he does eat a lot of beans, so one day Isaac was teasing, him, "Should I call you 'Beano'?" In reply, Aaron looked at Isaac, and then pointed at himself and shouted gleefully, "Beano!" His first joke?

What else.. we've noticed over the past few months that he is really clean. I think most kids go through this phase, but I'm not sure if he's in the normal range. He loves to "xi shou" or wash hands, and he always needs to have everything cleaned up. In fact, he really enjoys cleaning up, and he freaks out, "Cleamup! CLEAMUP! CLEAMUP!" if there's s tiny crumb on his hand or a drop of milk on the table. He was pretty unhappy when we didn't clean up his party decorations right away:

I'm wondering if this is a reaction to Isaac and I. We're not dirty, per se, but we definitely have a cluttered home. Or we did. Aaron's got an eagle eye, and when he sees a crumb on the ground or paper lying around, he brings it to me, states "Gah-bage" and then when I confirm, he throws it away. It's like having a tiny housekeeper who only throws away tiny crumbs and clean wipes.
I don't think he's OCD though, because he still thinks it's hilarious to knock down a tower of blocks or throw a full container of grapes onto the ground, causing them to roll ALL OVER the apartment to who knows where.

Which leads me to discipline. We're not quite sure what to do here. I can definitely tell that he's testing his boundaries, and he doesn't always listen to us. Hence the grape incident. We've tried timeouts, but he seems to enjoy them. The last few times I said threateningly, "Aaron, Timeout!", he replied excitedly, "Timeout! Want Timeout!" and scrambled to get out of his chair. So...I don't think that's really working. Any ideas out there?