They say the first 6 months is when a lot of the "puppy" stuff plays itself out. The nipping is usually due to the puppy teething and the pressure on their gums soothes them a bit. My guy did a lot of that too and at 5 months it's easing up a bit now. I looked at it I'd rather he try to chew on our fingers than on all the nice furniture, so spun it into a positive. Puppies are gonna chew on stuff, that's just how it is. Around 6 months is when their adult teeth come in so hopefully that gets better then.
My guys loves these gnaw sticks and it keeps him busy for an hour at a time and gets some of that chewing energy out.
https://www.amazon.com/gp/product/B075H2XVYB/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
On the walking him to the curb to do his business front, that sounds great and all but you'll get annoyed pretty quick with how often and inconvenient that will be. They have supplements that you can give dogs that supposedly make their urine less acidic and helps. You could also try to get a fake grass mat, put that in an inconspicuous area in the backyard and try to train him to go on that area only. I believe there's also a lawn spray that you can do to the area that he goes to help. Just some ideas.
My pup is overall pretty good, but we just want him to be as perfectly trained as we can, and they say to wait til 5 months old to start the obedience schools as that is when life really starts to click for them and their true long-term habits form. All the time before 5 months is when they are just learning the world and what they can and can't get away with. Our guy turns 5 months in about a week and on July 10th he's going to a 3 week obedience boot camp to work through all the little nuances we'd like to perfect. The trainer said he refuses to work with dogs younger than 5 months old because it's not as impactful. He also highly encouraged to not wait to do it much past 5 months old to not allow bad habits to set in. Sucks he's going to be away from us for 3 wks, but long-term will set the stage for him to be very obedient and curb any negative traits that would be much harder to correct down the line.