Aside from the green poops, everything sounds normal. 2 lbs in 2 weeks? Normal for a young breastfed baby. If you're worried that he'll reach his first birthday too fat to move, don't: weight gain slows as baby becomes mobile and starts putting his calories into reaching, rolling, squirming, crawling, etc. Rare coughing at the breast? Normal, since it's rare. Many young babies occasionally struggle with a rapid milk flow. Wants to eat every 2 hours? Utterly normal. Many babies eat every 1-2 hours, especially once they shake off their newborn sleepiness. Fussiness and irritability? Welcome to Normalville, population: you and your baby!
Now, just because all that is totally normal doesn't mean you're not dealing with oversupply. Green watery poops are certainly a possible sign of it, and many moms who pump very early on stimulate high milk production, which is why we always tell moms to nurse if it's an option, because getting the right level of supply is so much easier! If this is oversupply, there are 2 blessings: first, you won't need to worry about inadequate weight gain because more milk volume usually = more weight gain, and second, you may have an easier time than average maintaining your supply via pumping once you're back at work.
Here's what I would do, in your shoes: wait and watch for a week or so. The green poops could be a variation of normal, they could be a tummy bug. If the poops stay consistently green, start to manage the situation by allowing baby to set his own time limits at the breast. Let him finish breast A at his own pace before offering breast B. If the poops are still consistently green after a week or so of allowing baby to set his own pace, then revisit the possibility of block feeding.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"