#2
Try the C minor penantonic
Fender Stratocaster,Yamaha ERG 121 and 5 other random low budget acoustics
#3
You've got some chromatic movement on the b string, which means it doesn't fit into a single scale. There are lots of possibilities, though. Try C Ionian or Lydian for the first two "chords", Bb Ionian or Lydian for the last two. Or G Ionian/Mixolydian and F Ionian/Mixolydian, maybe.

Record a backing track of it and start jamming.