I would NOT start with a higher end road/race bike for one simple reason. Tire clearance. Having space to use larger tires can be a big deal and virtually all road/race bikes have trouble fitting anything bigger than 25. If you're a tinkerer and engineer type with mechanical aptitude you might start with an older 80's 10 speed and fix it up for your preferred use. My favorite ride for a long time has been an old Peugeot UO8 config'ed as a single speed. Old 27" tire 10 speeds have plenty of room for bigger tires on 700c rims. And you'll get to play with bike mechanics.

If you just want one bike, I recommend a cyclocross (like Bianchi Volpe) with the knobbies swapped out for slicker (but still big) road tires, or tourers (like novara randonee, trek520).