Hers's what my 2014 Street Glide owner's manual (page 58) says about the clutch:
"The vehicle can be started in any gear as long as the clutch lever is pulled in. If the clutch is not disengaged, the vehicle will not start when in gear."
There is no mention of a safety switch for the clutch lever in that section of the manual but I will look through the H-D service manual wiring diagrams to see if there is a safety switch. Will get back to you soon.