Finding a balance with Calvin...

So this world of having a 3 yr old  boy is proving to be very challenging.  Calvin is SO many things, I don't know if I can even begin to explain his complex personality emerging.  He's incredibly sweet, loves hugs and kisses, and will snuggle for a very long time if he is "in the mood".  He also loves to impress us with his jumping skills (off anything high), and if anything goes a tiny bit wrong or he messed up in any way, he throws a huge enormous fit of embarrassment and disappointment.  He rarely walks anywhere, he jumps, runs, skips, hops, and bounces.  His head is usually going a different direction than his body and he sometimes bonks into things without realizing it was there.  Generally he is an obedient child, putting his shoes away in the closet when coming into the house with out being asked to, coming to us when asked, doing things when asked...but sometimes he just doesn't do it.  Most times it is willful disobedience, other times I think he doesn't even know if he hears us or he has really bad common sense.  I am guessing this is true of any 3 yr old child.  Violet didn't seem to do those types of things.  But she's a girl, different kid....
For example, we were walking out to the van after church on Sunday, and Dave told the kids to stay on the sidewalk.  Violet and Calvin were walking 10 steps ahead of us and didn't hear because he was "in his own little world" bouncing around, and wandered into the parking lot.  Violet heard us and stayed on the sidwalk.  Nothing dangerous happened, but we had to yell at him so he would hear and finally come.  When he did come it wasn't like he was trying to be disobedient because he did come when we called him, but he was just super distracted, bouncing around, and much more interested in walking on the curb.
He also has a very messy impulsive side.  His instinct when getting something in his hands is to throw it straight up into the air.  A bucket of legos, a bucket of beads, anything...and they always have small parts.  I put the tinkertoys and bucket of beads out of their reach a couple weeks ago because it is dangerous to have those items on the floor with Vanessa crawling around now.  He grabbed his backpack hanging on the plastic hook near the garage door and tried to "hang" his body on it...which of course broke the hook, ripped the drywall off, and he fell and hit himself which resulted in lots of screaming.  Just yesterday, Calvin was left alone in proximity with Vanessa.  She was safely strapped in her infant car seat, and I had to leave them both to go deal with Violet about something else.  I had told him to stay in one place while I was gone, which he did, but he grabbed the handle of Vanessa's car seat and rocked the seat so far that it flipped her upside down.  Really!? 
If he ends up with chapstick in his hands, it gets twisted up as far as it will go and broken off and smeared everywhere on his hands/face.  He recently ate a snack of peanut butter on toast, and peanut butter ended up in his hair, his pants, and all over the table.  He's developing and changing in so many ways lately...talking in full sentences, showing us he has a wild creative imagination and the ability to play better with Violet, and expressing an interest in learning and writing his letters...and the "other" side of Calvin is just...hard.  I'm trying to find a balance between "oh, he's just 3..." considering his actions just part of his immature age and the other side...disciplining his for disobedience.