1. Yes. MIG only prevents modification or deletion; it does not interfere with read operations, so enabling it on your internal drive would not prevent you from making copies elsewhere, including copying to a different location on the same disk.
2. When MIG is enabled (it can be enabled/disabled on a per-partition basis), non-Macrium applications will not be able to delete or move files -- this includes you trying to do these things in Windows Explorer. The only exception (enabled by default) is Robocopy, but even it is only allowed under some circumstances. You can learn more about that from the MIG KB article here
. Note that it is possible to manually delete backups while MIG is enabled if you do so from within Reflect (under the Restore tab, select your backup > Other Actions > Delete), but there is no move functionality.
Also note that if you have MIG enabled system-wide and then disable it on a specific partition, if you ever run a backup job directly to that partition, MIG will be automatically re-enabled on that partition. If you want to keep MIG permanently disabled on a partition that is used as a backup destination, you have to disable MIG system-wide. Or of course you can temporarily disable MIG only on the occasions where you need to manually delete/move files to remain protected at all other times.