*** Not a lawyer ***
It sounds like you want to do what my ex-wife and I did.
For dividing assets and determining alimony, you’ll want to do a separation agreement. It doesn’t need to be filed with the courts at all. There is a sample on this site, and some detailed articles as well. Since you agree on the division of assets and everything and your children are almost all grown, it shouldn’t be too difficult to have one drafted or to draft one yourself and then have both of your lawyers look it over. Then you print out two copies, and you both go before a notary to sign them.
Once you have a signed and notarized separation agreement that addresses the particulars of alimony, I don’t know what circumstances if any might allow a judge to set it aside. I think one party would have to prove the separation agreement or the alimony portion of it invalid in some manner.
Regarding child support, there probably should have been child support being paid all this time while you were separated. And you and your wife can’t just waive child support, because child support is supposed to be for the best interests of the child and “the best interests of the child” isn’t something you or your wife can waive. On the other hand, you don’t have to follow the NC child support worksheets if you can make a decent case that some other terms satisfy the “best interests” criterion. In any case, your separation agreement should specify what child support you both agree to and (if different from the NC worksheet) why it satisfies the “best interests of the child” requirement. Again, if you and your wife can continue to settle any disagreements privately and neither of you invites DSS to involve themselves (note “inviting DSS to involve themselves” is a requirement when applying for various kinds of public assistance), it need never come before the courts at all.
Also, BTW, note that child support in North Carolina doesn’t necessarily terminate at age 18: if the child is still in high school, it normally continues until graduation, drop-out, age 20, or “fails to make satisfactory academic progress towards graduation”.
As for getting the actual divorce, see the thread “(Relatively) fast divorce?” in this forum for details on how my ex-wife and I did it. The key is to look at that “Judgement for Absolute Divorce Before The Clerk” form and make sure every finding is clearly satisfied based on the documents filed. Not counting the time to prepare all the paperwork, it took us about 3 hours.