Got 10 minutes and then I have to sign off and cook tea.
... accounts in part for the
grub-install: warning: file system 'ext2' doesn't support embedding.
Embedding is not possible.
Grub can only be installed in this setup by using blocklists. However, blocklist's are UNRELIABLE and their use is discouraged.
grub-install: error: will not proceed with blocklists.
This typically occurs with BIOS/MBR where we are trying to install Grub where there is insufficient space before the partition, specifically at the beginning of the drive.
We can address that if need be, (and the Live CD hanging problems), but the is another avenue to try Timeshift if you are able to access Elementary from the Grub Menu.
Even if EOS does not have Timeshift installed yet, you can install it using the PPA method Brian describes in #6.
You can then launch Timeshift and point in Location in Settings to where the Mint snapshot is stored, and choose to restore its snapshot. The default process, once the log file is parsed and size calculated, should show as defaults where Mint was housed, in its disclaimer.
If you are satisfied that that is correct, you can go ahead and tell it to restore.
A successful conclusion will entail a reboot when Timeshift is finished, and the reboot outcome will have Elementary on top and Mint 2nd, we can fix that later.
I can give you more detail when I am on deck tomorrow, or you can try it for yourself and report the outcome.
Nite all
Wiz