I assume you copied that info from the computers system profile (report), seems strange to me that the fusion drive would appear as 2 separate drives rather than the 1 "fusion" drive, what appears an your desktop as the mounted system drive? As I don't have an iMac with a FD I'm not sure of the exact behaviour within the MacOS -= perhaps someone else can chime in here
either way here's my idea of an optimal setup for running PT... I ALWAYS partition my internal system drive into 2 or 3 partitions, 1 for all my "Home" type use (Word. Excel, iPhoto, iTunes ect), 1 dedicated "Studio" partition for exclusive PT & Logic Pro use and 1 partition for a "Back Up" of the studio partition (cloned system and Apps) I also run a manual daily back up via Time Machine of everything. Setting up this way enables me to have a studio setup that runs cleanly and efficiently leaving the "Home" partition to handle all the day to day stuff - separate form this, ALL my media (audio, Samples/Loops, photos, videos, downloads etc) are pointed to and live/record to a completely separate 7200 rpm spinning platter drive (internal in my case) thus leaving the System partitions - Home & Studio - unencumbered and free to run the OS and the application (PT, Word, Logic etc), the issue I have with the fusion drive in principal, is that you seemingly have no control over what lives where with the OS taking an educated guess and constantly shuffling data as it sees fit (again, I'll add that I have no first hand experience of fusion drives so I may well be talking out my arse (that's how we say it in Oz) so I'm happy to be corrected) thus my suggestion of replacing the FD with a dedicated SSD which could then be partitioned and a 7200 rpm external drive to house ALL your assets.
As for the Apogee, check that the version of the driver you are using is compatible with the version of the MacOS you're running - this can be an issue.