They all sound good, but inherently no .mus was always going to be a problem. It won't be submitted to the site without it, and even if someone/s were nice enough to convert ALL those and others you're bound to make in the future, it really wouldn't be fair to them.
If you use something like Sibelius or MuseScore you might be able to convert it into MusicXML format, which would be easier to import. Converting from MIDI to MUS is really messy and only gives us notes. Rarely do key sigs, time changes, grace notes and any form of formatting, articulation or dynamics translate properly if at all.
Hope you work this out. 
Thanks for this feedback. Now that I think about it, you've got a big point, and it
wouldn't be fair to everyone else to convert my files. If I get the chance I'll get a finale product. (I'd better start saving

) What's really fortunate is that the program I use can export Midis
AND MusicXMLs. MusicXMLs never crossed my mind because I always found them pretty messy, but if that works best I have no problems
whatsoever.
(Just to let you know if you read this again, I had no idea what I was talking about because my program can't read XMLs)