When you go to Ashville, I would take State Highway 74 through Chimney Rock rather than the interstate for your last leg of the drive. The area is scenic. Lake Lure is beautiful.

Welcome to North Carolina!
a. which airport? Probably RDU or CLT will give you the best fares and best chance of a non stop from CA.
b. Charleston is in South Carolina and is well worth a visit. It is a beautiful city with great architecture and some of the best restaurants in the USA.
c. If you love history you should make a stop at Old Salem in Winston-Salem. It is right off I-40 between Wilmington and Asheville.
d. Wilmington has a lovely waterfront and some interesting historical buildings. It is also a great beach area.
e. I recommend you click on the North Carolina tagged posts in the forum and see what intrigues you. There are a number of regular posters who will be glad to help you enjoy our beautiful state.

Thanks for the geography lesson! Boy, am I a dummy!
I will follow your suggestions and let you know.
Looking forward to the trip.

No dummy, at all. Charleston is VERY accessible for your trip, and you should consider it.
How long do you have. It could be a GREAT trip, but we need more info.
Leland/Wilmington is only about a scenic 3 hour drive to Charleston, for example.
Then Charleston to Asheville is about 5 or so hours, not so scenic, but easy. Then Asheville to Wilmington is about 4 hours.
Fly into Charlotte or RDU for maybe best and most direct fares. Then rent a car, drive to Leland and do the RT. There are other ways to do it probably, but that will be a start.

If you can, fly into RDU, drive to Leland, then to Charleston, then to Asheville and fly home from Charlotte. Flying open jaw will save you a couple hours drive time. 2 weeks is plenty of time for this.

Southwest has flight to Charleston and Greenville SC . Depending on the time period they are often $50 to $150 cheaper than othe airlines and offer two free bags. You could fly into to Charleston, rest, sightsee then visit the family in Leland. Then visit Asheville. Other than Asheville itself which has limited flights Greenville is closest.

The only problem is see is the cost of getting a rental car company to accept a different return location.

You can actually fly thru CLT and on to Wilmington

Sounds like a fun trip.

I would add that August is hot. As you look for a hotel in Charleston you'll see that prices in the Historic District are higher than others in the area. I highly recommend you stay in the HD, so that you can pop back into your room for a cool-off break. Plan to tour early in your day, then enjoy the local cuisine during the late afternoon.