Midi Export
Midi export needs attention. If the song has more than 16 instruments (violin counting as 3 because of pizzicato and tremolo), the instruments in the midi will be messed up. I know this can't be perfectly fixed, but it can be improved on. Also, pitch bends are not exported properly.
Comments
As you may be aware, MIDI really only handles 16 channels in a completely seamless manner. Anything more requires some form of juggling. In general, what MuseScore does should normally work with most other software and hardware. Is there something in particular you think could be done differently to improve the situation? Also, what specifically are you doing with pitch bends? Do you mean the guitar bend notation? Wouldn't surprise me if those don't get exported indeed. Feel free to see if there is existing feature request in the issue tracker for that, and if not, go ahead and add one.