As X3N0-Life-Form said, you don't need to install FreeSpace 2 retail yourself with Wine or CrossOver or something like that. The FSOInstaller can take the GOG FS2 installer file (setup_freespace2.exe or whatever it's called) and extract the FS2 retail data from it for you.
Also as I remember there was an issue with the Mac builds of FSO 3.7.4 that comes with the FSOinstaller, don't know if that was ever fixed. Can you get a copy of 3.7.4 from the
release thread and use that instead of the build from the FSOInstaller?
EDIT: Also, your computer is pretty old, not sure how well it'll be able to run the game. You should certainly be able to run the original retail game without any mods, maybe also the MediaVPs 2014 (I think that's the latest MediaVPs version?) but newer campaigns might not be playable, not sure. Someone who's more of a graphics coder would know for sure. At a minimum, once you have a build of 3.7.4 that works, you'll probably need to go to the launcher's advanced settings tab and under the "Graphics" category of the list of checkboxes (aka "flag list"), check "disable deferred lighting" and "disable lightshafts". Even disabling those might not be enough, not sure, but it's a starting point.