I'm so glad to read that you've decided to go. Remember that in addition to the 50% chance of rain, there's also a 50% chance that the weather forecast around here will change completely every 24 hours. And also a 50% chance that the afternoon weather will be completely different from the AM forecast.
Just be prepared for any combination, including walking or biking with sun overhead and mud underfoot.
… We are thinking about a 25' Class C without a toad….. Would it be unreasonable to unhook everything to go to a restaurant or maybe go sightseeing and then hook back up upon return? … .
I've done exactly what you plan to do, and I found it perfectly do-able. A smallish Class C can find a place to park in most parking lots (stores, restaurants, etc.) or even park on the street. I used mine as my suburban daily driver for a year!
You won't have to "un-hook everything" if you don't hook up everything in the first place. Your RV will come with tanks for fresh water as well as waste: To stay mobile, use those and only "hook up" for a few minutes to fill or empty as needed, every few days. Just plug in the electric, and maybe not even that for an overnight. Enjoy!
Non-macerator setups are more common. As one company rep stated firmly but cheerfully in a video I watched recently: "Gravity always works." Features like macerators and electric steps set off my "KISS Principle" alarms.
When I'm just getting from Point A to Point B, finding a campground for the night is a hassle, as well as an expense. Compared to a typical campground, Walmarts are :
Easier to find and access
Always level, pull-through parking
Always answer their phone
Better camp store
Better security personnel
Cleaner bathrooms (though not as well-equipped)
No check-in, nosy neighbors, kids running around, smoky campfires, or loud singing into the night
I'll typically head out early in the AM, do touristy stuff mid-day, then finish the day's mileage quota later, on my way to the next WM. Living in the northeast corner of the country, I often have to travel a couple of days just to get the "real trip" started!