Its certainly all road bikeable - some nice places en route - i did it in 3 fairly easy days.
You have two options for car ferry across the lake, Konstanz and the actual Friedrichshafen ferry but you can also take a bike on most of the passenger ferries.
Are you camping or B&B?
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!