Why do you need both a Tachyokinetic Converter and an RCS Accelerator on a Defiant? Thats almost as bad as a friend of mine who purposefully put a Tachyokinetic Converter and 4 RCS Accelerators on the Jem'hadar Attack ship for the sole purpose that he wanted to see how fast he could turn. Your killing your own DPS capabilities by running that RCS Accelerator instead of the Zero-Point Energy Conduit. And yes, the Zero-Point Energy Conduit is a universal console and thus can go in the engineering consoles slot. It does not need to be in the science consoles slot.
I want my turn rate as high as possible. If I am to out turn a Jem'Hadar or BoP, or at least match their turn rate, I can stay on their aft if they are the runner type. I can also swing around faster going in reverse, so I can beat my target to getting them in my fore arc. I've chased many escorts and BoP without them being able to shake me.
I'm fully aware that Zero-Point Energy Conduit. With all of the passive critical hit bonuses (Romulan T2 reputation passive, Romulan BOFFs), my critical hit is ~10%. 1.8% more isn't going to be that significant.
As for my DPS, it's pretty rare for someone to out-damage me in PvP or elite STFs.