Solid build. I'd actually switch Dual shot with Savage shot, and power shot with Sundering Shot. Once, you can max out marks, I'd switch Appy for Read the Wind.
Or eventually use kindle/ignite and keep dual shot to double the extra damage. Yeah that's a good build. Think about switching to /Mo too when you get to Senji's Croner to have a reusable rez as you don't use /E skills.