Question 1:
No idea.
question 2:
At the moment i experience several issues with multiple sonos devices on homey.
One device works ok. with 2 of more, the device selection is a mess (plays on other than intended device/ controls the other than intended device). I’ve got a confirmation from Athom this should be fixed in the sonos 4.0 app (the homey app that is). which i expect with homey 2.0 ish??
quesstion 3:
This can (at the moment) only be done by hardwiring the Homey jack output to a sonos input.
question 4:
Play from playlists. see this topic Flow with music play only play first track from playlist on sonos
for a way to get it to work. (sonos app is still a litte tacky at times (imho).