Four MuseScore notation questions

I have the following 4 MuseScore notation questions:

1. How does one add a diagonal line showing the melody moves from one staff to another like so:
   

2. How can one have notes on the same beam but on more than one staff, like so:
   

3. Sometime, the treble clef and the bass clef have different dynamics. When I set these, MuseScore renders the notes on both clef with the same dynamic sound level on playback. Is there any way to fix this so that the notes on each clef can be at a different loudness on playback? Example:
   

4. In the following, “perdendosi” is followed by some dots to show that this occurs over the length of the measure. Is there anyway to notate this in MuseScore?