Hot pulling a drive in a RAID 1 is not a guaranteed way of ensuring the backup is good. If you pull it while unwritten data is still in memory, or is in the middle of a write, the backup will likely be bad. At a minimum, run the sync command to flush the cache.

Swapping the drives after the OS has been shut down should work fine.

RAID is not generally a backup solution, it's protection from downtime in case of a drive failure.