Robes should be clicked together. You will get the biggest bang out of VoA robe when you are critting the most and your crits are hitting their hardest.
Class robe for Prophesy of Ro expansion is a quick cast dot that doesn't share a timer with any of your needed clicks.
Staff of Axsomethingorother for Old Man Murphy Monster Mission Raids is a quick click and refresh DD that can add a tiny bit of damage and can crit.
The mostly useless Timeshear from the SoD expansion can be used right as you engage, click it, Lifeburn and boom your hps are back.
Not adding to DPS but I find the Tash Orb from Old Man Murphy group Monster Missions is worth getting for the tash click.
That is all besides some low damage dot clickies that aren't fast cast (fast cast is nice since can do it between spell refreshes) like PoP Elemental Pants for Pyrocursor, Tacvi Dagger of Death (can crit, but isn't effected by foci), and depending on how dotted/debuffed things get on your raids, you may not want to use them so real dots don't bounce.
That is all I can think of without logging in to see what clickies I have.