using hot swap for OS..

I wouldn't advise it. At best, Windows will complain and you'll have to replace the drive and reboot to recover.
You should only hot-swap drives used simply for data backups and storage, and then only if the drive isn't being read from/written to.

My understanding is that the term "hot swap" means you can swap a drive while Windows is running (ie no need to shut down or restart), but not if the drive in question actually has the active OS installed on it.

Feel free to try it of course. You may prove me wrong.