Cant inform you on your bike choices a I ain't familiar with them. I do have a similar 7 mile commute (recently voluntarily increased to 10 miles when time allows), also I jut rode a 50 mile loop this weekend very similar to what you describe.
My old rigid '88 Rockhopper has 26" wheels and I'm really liking the 26" x 2.0" Serfa Drifters (REI) I put on last month.
I think you will find uneven sidewalk riding considerably slower than roadways, at least that has been my experience.
Mike