1 and 3 sure sound like trouble with your controller on the phone reaching the application on the speakers. Not sure about 2, though.
There are two more common reasons for this. First, of course, is just wifi interference. However, since you mention the update to S2 (technically, just a simple software update, like any from Sonos, it works exactly the same as S1 currently), I am leaning towards a duplicate IP address issue. Try unplugging all Sonos devices from power. While they are unplugged, reboot your router. Once the router comes back up, plug back in all Sonos devices. Wait a couple of minutes before testing. This process has other benefits beyond merely duplicate IP address issues, of course.
However, if neither suggestion fixes the issue, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it, or post the diagnostic number here for a Community Moderator to pick up.
There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.
When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.