I run PSO at 2560x1440
Consider setting the custom Window to 2560x1440, but set the HUD to a lower resolution, such as 1280x720. This will allow you to be able to see the HUD much easier.
I've noticed the music issue, as well. As Trigunman mentioned, usually only happens once, and is a minor bug. Aside from that, I use Radeon Settings to change how the game looks.