I owned one of these from 1974 to 1976. I crashed it once (railroad tracks at speed and loss of stability) and got hurt pretty bad -- no broken bones but a lot of bad abrasions. The CB350 is a lovely bike -- reliable, light, nimble, and powerful enough. It will go 100mph with ease and at 70 to 80 it´s not even breaking a sweat. It´s great for riding around town or taking a blast on back roads.
But I wouldn´t recommend it for any kind of distances -- your hands will go numb from the vibration after half an hour or so, and it´s much less stable than a bigger bike. For touring you will want something bigger and smoother -- like a CB500 Four, say, from the same era, or better yet, a CB750. You will feel much safer and more comfortable on a big four on the open road.