Hi,
I suggest looking at bikes that will take a medium size tire. They will ride a little nicer over sidewalks and bumpy paths and be less skittish offroad.

As an example of the breed, take a look at the Specialized Seqouia. A lot of bike companies make something like that now, but it is one of the best of it's type. It has drop bars, and can go pretty fast. But it will take a nice large tire and has other features that make it much comfier on a long ride than the performance bikes you have been looking at. One thing I don't care for about that bike is the tires, they have kinda a hard ride, but you can have the dealer put something different on if you like it.