The iMac booted to Mint after the install successfully, however, as before the wireless drivers were missing, so for that solution, see the spoiler above. The only question now is if the install/boot ...

TLDR; yes, it is possible to add an SSD to a 2011 27" iMac without going through too much hoopla. Between everyone having issues finding parts, non-workable guides (due to parts), and general ...