2 questions

We’ve been married for 21 years. Two sons, ages 18 and 15. My wife works full-time, salary $3500/month. I work as well, salary $8500/month. Oldest son starts college next fall, cost to be (initially) about $1500/month. Our marriage is and has been for some years really nothing but an economic partnership. I’ve felt like it would be best to wait it out until our youngest goes to college, but that is becoming more and more difficult. I have a couple of specific financial questions to ask:
1.As my income is larger than hers, I gather I’ll owe her support under N.C. law. How does the court typically look at college expenses in all this? Though my wife and I don’t agree on much, neither of us wants our son saddled with student loans. So would college be netted out against payment to her, or kept out of alimony completely and we’d have to come up with a separate agreement on paying for college?
2.After completing study and passing some exams this November, my wife’s income should increase by at least $2000/month. Would that increase really have much of an impact on what my alimony will be?

You two can come up with an agreement that would state whatever specifics you can agree on for alimony, child support and ED. As long as what you put into the agreement is not illegal then there is nothing to “fight” over in court. You can agree that you will pay her a specified amount until her salary increases or for a specified length of time. You can agree to pay whatever portion of college expenses as long as the child is working dilligently towards degree/graduation…
NC does not required a parent to pay for college expenses as a general rule but if you put it into an agreement, then that will hold up in court as a contract. Your spouse does not have to file for alimony or child support with the courts if there’s a satisfactory agreement signed by you both that you both stick to.

If you take the alimony to court, I do not know if her increase of income will have an affect on the amount. The child support for the younger child will be mandated by NC guidelines based on your current salaries, number of overnights with each parent, insurance costs and other extraordinary expenses paid by each parent.
The college expenses would still be subject to agreement…

You will have a child support obligation for your children until they reach age 18 (and beyond age 18, up to age 20 if they are still in high school and making progress towards completion). Beyond that a court cannot require either parent to be responsible for college expenses, unless you agree to do so in a separation agreement, which the courts will enforce. Your agreement to pay your child’s college expenses can affect alimony in that it will increase your expenses, leaving you will less “excess” to pay alimony, though it is questionable how any particular judge would account for this.
Since alimony is based on a demonstrated need, your wife’s increase in income will affect alimony by reducing the need she can demonstrate.