North Carolina does in fact have a lot military traffic. There are several MOA (military operating areas) as well as "low level," training routes. We have both Air Force and Marine air bases in the state. Throw in several in Virginia, South Carolina and Georgia plus a reserve base at Maryville, TN (airborne refueling aircraft) there is no telling what aircraft you will see.
I live in the far Western corner of NC and with the mountains we get a lot of low level mountain training. With the good folks at Lockheed next to Dobbins Reserve base in Marietta, GA you even see some of the big boys and especially C-130's, Back when I was a kid they were still testing and developing the C-5 Galaxy and I'll never forget the first time I heard it passing over at about 12 to 15 thousand feet. My dad who had been with a B-29 bomber group on Saipan during WWII marveled at the size and power it had.
Perhaps my favorite was a brief time when we would have B-1's, B-52's and C-141's doing low level. I swear they would be so low they had to pull up slightly, make their bank then settle back down to their cruise altitude. This was necessary to give clearance for the wings since they were so low.
Only a few times did I see F-111's but they made quite a show.
Honestly, the lowest I've seen pass through were the Navy/Marine A-6's and S-3's, you could smell the kerosene smell from the engines they were so low!
There are Naval training flights out of Pensacola regularly.
Sadly in my lifetime, we've had 6 or 7 military crashes within a 50 mile radius. The most deadly was a C-141 that flew into a mountain in the Cherohala Skyway area several years back. The most recent was a Navy T-45 trainer that flew into terrain less than 3 or 4 minutes after passing over my house. At least those onboard had a heck of a ride while it lasted as the weather was beautiful and the mountains awesome!
We also got our share of choppers. My favorites were the MH-53 Pave Lo's and MH-47's special operations choppers. The MH-53's would come up from Hurlburt Field in Florida and operate out of Dobbins and the MH-47's came down from Ft. Campbell.
As to doing away with the speed limit signs, you must have been born under a lucky star as our state highway patrol local district (based out of Bryson City, NC) will give you 4 or 5 over the posted and burn you a new one when they want to.
You'all come back again, you hear!