I have no problem with insurance in Skandinavia, where insurance is known for being a pain in the a** to find. My sportscar was harder to insure, and it was a factory build?!?!
My sidecar (California Sidecar) set-up claims to be a 2-3 minute break-off job, and 10 minute remount. I take a little longer, but the "quick" connect settings are good, and do allow for pulling the rig apart, and remounting the two together, without needing to do a realignment, or loosing your last settings. As mentioned above, yes, they are a pinned job.
And lastly, no, permanent alteration is not required. The mounting hardware is bolt on, bolt off. Actually, it did require a small section of the front fairing to be cut away....about the size of a 50 cent piece, so that fairing would have to be replaced, it the sidecar was to be permenantly removed, otherwise, it would be noticable. It is the small three bolt fairing, which could be had for about 30-50 bucks, if need be.
I have several bikes, for different riding styles and conditions, so I do not mount and dismount the hack often, but it would be a viable option! Good luck!