Hmm. To run FRED open, just run FRED2_Open instead of FRED2, and use the -mod option to enable mods, eg, fsport primary, relying on mediavps secondary would be -mod fsport,mediavps... or, just the mediavps would be -mod mediavps
To get FS1 music working, you'd need to copy the music.tbl (or tbm, or both if they are there) to your mod directory, as well as the FS1_warble.vp (Yes, you are going to have to make a mod directory for this to work correctly AFAIK.)
Sorry if it seems confusing, perhaps karajorma or someone can explain it better or make corrections. I know Goober5000 was the one who got FS1 music working correctly with FS Open.