Launchbox will automatically combine multi disc games as long as they are named correctly, so like you say xxx Disc 1and xxx Disc 2 will be added to one game entry during import, and if you want to load the second disc you just right click the game and select disc 2. Also i should add that you only need to import the .cue files for ps1, and the .gdi files for Dreamcast, as those files have the data for the emulators that is all that is needed to be imported into launchbox.