I had a house for many years in this area, but I hesitated to respond because no great suggestions for you came to mind. In August, things are getting tough for fly fishing mountain streams. I love the Cashiers/ Toxaway area. It's scenic, but great easy access fly fishing opportunities are just not numerous. Best activities here include hiking, shopping, eating at fancy restaurants, and sipping your favorite beverage on the back porch.
You asked about Panthertown. It's listed on the NC fishing trail, though I often wonder why. I've hiked and messed around in this valley at least thirty times. I've never seen anyone catch a fish, though I've seen a few fishermen. Two small streams converge to make the headwaters of the Tuck river. The stream has a sandy bottom, as does the whole valley. It's called an upland pine bog. The bog gives the water a brown tea color. The only structure to the river is given by large rock shelves that make waterfalls and swirly holes, and fallen logs.
Our family has always enjoyed hiking in Panthertown, and picknicking at Granny Burrell Falls. It's a great place to spend a hot August afternoon. If you caught a brook trout here, it would be 5 inches or less. It's easy to get turned around in Panthertown. Slickrock expeditions sells a great detailed hiking map of the valley. You can buy one on-line. I wouldn't go far in the valley without a good map. There will be other tourists hiking and hanging out at the popular pools and falls like schoolhouse falls. If you want an ultimate expedition, you could try to bushwhack into the Devil's Elbow gorge. No trail here. Thick rhodo and sheer rock walls. I've never done it. Check out a good topo map and see if you have the heart.
My best thought on Panthertown would be to take the family for a hike, and bring a fly rod along. Have lunch and swim, and if you caught a fish or two, so much the better. 3 weight 8 foot rod would fit the bill here or any stream in this area. Small parachute adams or yellow caddis with a tiny bead head dropper are all the flies you'd need.
You asked about pike and musky. No reliable populations here. Yes, your best bet for smallmouth is the Tuck. Several guides are running float trips here, including Eugene Shuler who has an advertised special. Best fishing lakes, including stocked trout lakes, are all private.
Other area rivers include Chattooga, Whitewater, Toxaway, Horsepasture, et. al. but August is a tough month. You should ask at the local fly shop in Cashiers, Brookings. I hope they give you better suggestions.