GJC,
I'm with you, take it slow. The engine needs at least 2,000 miles (or more) to break in so you might as well take it easy on your "break in" too. Your comfortable top speed will increase too. And, the engine is pretty smooth to begin with but feels even better as the parts wear-in.
As for rain, once you get stuck in a heavy downpour and make it home in one piece you'll understand that even having only two wheels you still do have pretty good traction. I've been riding since the 70s and it wasn't until a cross country trip 20 years later that I got stuck in a heavy storm. Since then, I take it slower in the rain but have gained confidence so I don't freak out and tighten up at the first sign of water on my visor. Same goes for riding in dirt, gravel and sand. Not easy but the more short rides you experience the better you'll be at it. Consider taking a couple of rider training courses to gain skills and confidence.
I-10 in Alabama is a busy ride, but doesn't compare to I-10 in Southern California. ;-)
Enjoy your new ride!