I've done some more riding and I think the road buzz is pretty much due to user error. I recently went back to the LBS to pick up some nice padded shorts (lesson learned...don't cheap out on the first pair) and I told my sales guy about the issue who asked about my form, was I holding on with a death grip, was I using my core like he suggested, etc? When I thought about it longer I realized how many things I could change so I went on another ride with those improvements in mind and the ride was much better.

I plan on strengthening my core and I ordered some bar ends. My tires are 700x32 so I think the size is probably okay for now, but I might experiment with the pressure a bit.

I can always get a road bike later on if I want something lighter/faster, but for now I like that my bike has various functions and it's still an enjoyable ride.