There seems to only be a developers mailing list for Musescore. I'm not sure if I should bother them with end user questions. I'm posting a couple of questions here as well as somethings I've figured out:
Questions:
* How do I select multiple measures in order to copy/paste? (I can do single measures...)
* How do I completely remove a measure from my score?
* How do I enter a multi-measure rest of the form |--- 4 ---| ?
* How do I unbeam two notes?
Tips:
*Enter the key signature for a score: You don't have to be in edit mode. Type # and drag the key signature you want to your first clef.
*Enter a double bar or a begin/end repeat: Create > Barlines. As above, drag...
*Tie two notes: Escape to leave edit mode. Select the 2nd note. Type +.
I think I did get this working... Unfortunately my notes aren't accessible to me right now. I will try to reply tonight from home. Please remind me if you don't hear back!
I just took a quick look at my musescore charts and none of them have multimeasure rests. Guess I didn't figure it out. I tried just now and failed to make it work. There is surely a newer version than my 0.9.1... That nabble post might have been referring to a more recent version.
The interface is weird until you get used to it. I would think that beaming rests would work like beaming/unbeaming notes. I assume you have figured out how to enter 8th notes? By default they are beamed in groups of 4. To unbeam:
1. expand beam properties on the right
2. drag the "lone 8th note" icon onto a presently-beamed note (the note head turns red). Drop the icon on the note and it becomes unbeamed.
Now try re-beaming by dragging and dropping the other icons.
Maybe you already knew this...
You can always export to Lilypond and tweek there, as I'm sure you know.