Paying it off would help a lot. Then it would say PIF and not settled for less than amount owed. Which would look better to future creditors. But the lates that go with it that led to the CO will hurt the full 7 yrs. Usually a CO hits after 180 days late. If you only have 1 card. You need 3 cards and a loan for the rebuild FICO bonus. But I'd hold off on applying until Disco is paid and reflects that on your reports. Then seek more revolvers slowy as you rebuild. Welcome to the forums.
Yeah Disco isnt known to be that generous. But they will let you back in around a year or so out. They dont blacklist you like others do. So you could be back in with them in time. Good luck! Lets us know when the 0 hits and we'll lead you into rebuilding some more.
Will probably take a good 30 days at least to update. I'd wait at least 3-6 months after it updates to give it some time to age.
Nah if Discover already CO'd it and the balance on their reporting is zero, they already sold it to a CA and will have nothing further to do as far as negotiating. Recalling the debt with the OC is generally done for medical collections or wireless cellphone bill/internet/cable collections.