Conventional legal mechanisms against your home server cabinet can be handled via full disk encryption and a reed switch on your cabinet door connected to your power strip.
I hotswap drives all the time, it's not a problem and makes a harddrive swap a 30 second task instead of a 10 minute task and doesn't incur downtime either.
Most consumer hard drives (and indeed bays) are not designed for hotswapping and it can cause damage (though maybe modern build quality is good enough that you'd be lucky most of the time). "Downtime" on your home server in your closet is a minor inconvenience at worst.
The SATA connectors are designed for hotswapping, the ground leads are longer than the others so you get nice properties when connecting and disconnecting. I'd be mildly concerned about properly stopping the drive that's being disconnected, except it's probably being disconnected to be replaced. I don't see much difference between connecting a drive and turning the power on to an already connected drive.
I use NAS Harddrives which are built for hotswapping. I have no idea why anybody would use a consumer harddrive in a RAID Array, the price difference is 10€ at best AFAIK.