Hi there!
I also run Marble Blast on Wine, so I might be able to lend a hand. Would you be able to provide a bit more information about your system? Namely, the Linux distribution and version of Wine you're using, as well as your CPU and graphics card specs.
Additionally, if you're able to provide a copy of console.log (found in the root folder of MBG), that may give some additional insight.
QuArK is still a good map editor
You know what's boring? Opaque marble skins. You know what's not?
Glass Marbles!