Physical Danger
There haven't been too many reports of a violin bow to the eye or a singer tripping, falling forward, and swallowing a microphone, so it's more or less safe. You will, however, be doing a lot of traveling, possibly lugging around heavy equipment, and perhaps incorporating some movement into your act, all of which could potentially result in an injury of some kind. So just be careful and try not to get into any moving-a-piano-into-a-bus-while-dancing accidents.