You have provided good detail so you'll get decent responses. But you missed one thing... what is your budget?

I'll start the ball rolling. Based on your "gravel and impressive potholes", I think endurance road might not be a great fit because you probably want wider tires for these conditions. 28mm minimum, depending on your definition of gravel. I doubt there are "road bikes" that accept wide tires, although touring bikes might fit that niche. I don't know who makes good touring bikes, but it won't be Trek, Specialized, etc. Surly, Salsa Vaya, Jamis and probably other brands. Touring bike will also be a good choice because it will accommodate fenders and rack/panniers. Touring bikes won't be as light as road bike. Next, is CX bike. CX bike will take wider tires and be durable. May or may not be able to fit fenders and rack. Hybrids will take fatter tires and and offer a more comfortable ride on crappy roads. The 26 miles, though, says you might want to consider a bike with drop bars since it offers more hand positions and more aero position. It took me several hundred miles before I felt comfortable riding in the drops; confidence and knowing the feel of the bike will come with time.

I think the Giant Invite 2 might be a good choice. Jamis Aurora looks in the same price range and features as the Invite. Salsa Vaya 3 is above your price range, but would be a quality bike. Surly Long Haul Trucker might be at the top of your price range.

The Giant Avail is a sweet bike, but it looks like no fenders and no rack for that bike. The question is how pothole-y are the potholes and how long a stretch to you have on gravel? Perhaps a biker buddy who lives in your town can help answer that question.