I'm going to sound difficult, but I'd like to see the designs for the "do everything" plate. Personally, I think it should stick as a navigational deflector while you have the ports above it configured for Plasma Torpedo firing (Center being the torpedo launcher, and the left and right nozzles firing bolts). Leave reverse power for thrusters or inverting the warp field to cause a reverse-motion effect. After all, with the exception of the Scimitar, I can't think of any Trek ship which has engines directed forward for reverse thrust.
Well, this is based in some fandom and some observation. First, most note most other races do not use visible navigational deflectors, with the exception of Cardassians and Romulans, at least according to fans. It has been said that the glowing spiral disruptor on the nose of Cardassian ships, as well as the Romulan nose green port are probably deflectors of some sort, and have also been seen firing bolts or beams of energy. We have also seen the deflectors on Fed ships used as a makeshift weapon a few times. The Romulan port in front has been seen firing both bolts and beams of energy.
Now, we all know the nature of plasma torpedoes...torpedoes with no case, simply a confinement module in the center that loses containment over time, lowering the power of the torpedo over distance. Note, Romulan torpedoes are incredibly powerful at close range, but not so much at long ranges, and are much slower than Photon torpedoes. I contend that all Romulan weapons use warp plasma for thier weaponry. Knowing the nature of plasma, one can conjecture it could also be used as a repulsive field.
As far as the reverse engines, technically all engines have the ability to reverse (though I have to admit im not sure how you can reverse rear-only engines), so I dont feel that a reverse engine use for this port, though limited in power, would be a stretch. I just decided for the Romulans to indicate the strengths and weaknesses of thier designs. This is just my conjecture of course.
Romulan ships remain underpowered at warp, with the exception of this design. They do, however have a huge surplus of energy. This allows extremely powerful weapons and sheilds, and quick firing rates. Torpedoes are slower and less accurate, and are weak at long range, but extremely powerful at close range. Romulan ships are basically ultimate alpha strike vessels, but have less staying power over longer engagements. Armor varies, but it much lower than Klingons.
One explanation of the BOP's Warp engines is that they are impulse Powered. Specifically, the same engines that drive a constitution's Impulse engines are also what makes the warp drives go on the Romulan BoP. This means that warp power works, but it is horribly underpowered.
I've also seen BoP era warp drives termed as "Stutter Warp" by Starfleet Battles.
The Starfleet museum mentions that perhaps the romulans detested the idea of annihilation of dual forces (antimatter and matter engines), which explained their transition to quantum singularities later. If they bypassed M/AM reactors altogether, they'd still be using fusion/fission reactors to power thier vessels in TOS (which is what powered the impulse engines of the TOS connie, IIRC)
I dont really like the detested annihilation concept. I would rather go with a more convential explanation, something like a stolen design, supported by the original series, and add details that support show comments and are more standard, like a reduced efficiency leading to a very inefficient plasma creation process.
I never saw the BoP as a "failed" design. Considering it's weaponry was more powerful than the Klingon contemporaries of the time (and even the constiution), it at least had some sucesses. Old, yes, but still had a lot of potential.
The weaponry power is not in dispute. As I have mentioned, Romulan weapons remain the most powerful known among the major players in the galaxy. The basis of the designs "failure" was more its very short range and testy engine design. The original BOP was redesigned in my conjecture (note: I contend the BOP in STSfS was, in fact, an original Romulan design aquired by the Duras family during thier collaboration with them, and redesigned for Klingon use) and was fitted with the new Quantum Singularity drive, which was disasterous (the ships imploded on themselves). The design was shelved, but was used successfully by the Klingons using thier M/AM core. Later, the design was revisited (my Vdan) and this ship was the designers tribute to the original BOP designer.
Now, on to the latest. I have tweaked the design a bit more, still needs a few more details. I added the wingtip details I wanted, finally got them right I think (I wanted them to be on the subtle side) and worked on the connections for the warp nacelles to the wings. Let me know what you think sofar.