If you have any questions about what gear you should use or about your specific DPS stat weights, you should use Shadowcraft to get the answers. WoW is a game with dozens of different mechanics and complex intersections. There's no way to guess or intuit what's right for your rogue. Every rogue has different access to gear, and you're always limited by what actually drops. You shouldn't focus on trying to theorycraft in a gear vacuum, because the gear you currently have is important in planning the proper upgrade paths.
That said, there's no reason you shouldn't understand some of the underlying mechanics that determine what gear and stats are good for you. The newest mechanic in WoW is the Real Proc-Per-Minute (RPPM) system, which affects several proc-based effects like our weapon enchants, trinkets, and the legendary meta gem. RPPM is a very different system for procs than we've seen in the past.