Default [Q] New Phone Queries

I got the M8 yesterday, but I have a few queries.

Where is the gallery / photo album widget? I had one on the HOX.

When I plug in a set of headphones that have a single button on the mic, what are the button combos?
I was hoping to press once to hang up calls, and use it to control the music player (one click to pause/play, two to skip tracks)
Can you change what button controls are?