1 - Bell Citi. I like the tail light mount, the color, and the reflective accents. And really like the (sold separately) mirror made just for its visor. Oh, and it's pretty comfortable too.
2 - ~$30, on clearance at REI
3 - If I deem it no longer to be safe. If that were right now, I would probably replace it with a Bell Muni. The Muni has integrated rear light, accommodates the Blackburn Flea front blinkie via a 'perch' on the visor, and also will mount the Bell Flip Mirror.