The lack of poops is perfectly normal, someone once described it to me as babies being exceptionally efficient :) Plus they *are* on a liquid diet!
DD often went up to two weeks as an infant. And now baby G. goes several days at a time. His longest stretch has been 6 days so far.
Snuffles/congestion is normal too :) G. was stuffed up for about a week, DD was close to a month before she was completely clear. I too, was worried about allergies or what have you but she is 100% normal.
As for NIP, I've never hesitated to sit down wherever and feed baby. It gets to be a lot more challenging when I have 3 other munchkins in a store who get restless when I need to sit in one spot for 10min. Mastering nursing while babywearing has been a godsend!
I primarily use a pouch sling over my left shoulder so baby is at my left breast. If I need to feed from the other side, I slide the sling around so it's a football hold. I try to layer my shirts so when I pull my shirt up, I'm not exposing my muffin top to the world lol! Otherwise I'll wear a button down shirt or one with a low-cut top. The advantage of the sling too is that I can pull it up and it covers everything, it gets a little more challenging when baby gets older and is more wiggly, and starts pulling my shirt around with his hands . Always new challenges!
As for the Mei Tei (I've never used a Moby but it's the same principal), I just loosen the straps so they're sitting lower and right at boob level. Then when they're done, I tighten it up again.
We're having a crazy week here, lots of stuff piling up which is annoying and stressful. I had my first big outing (aside from the local grocery store/library) with all 4 kids yesterday and it went pretty well! The older two get so spacy after lunch (nap time!!) so that's frustrating but the baby enjoyed being worn and doesn't mind the in and out of the car-seat now too so that's a bonus :)
Poor DH is feeling really deprived because he hardly gets a chance to hold the baby, I feel terrible because he falls asleep at night with him on his chest BUT I have to do a dream feed and take the baby away from him.