They do need to do a little rework of the interior, but I am not sure it really needs that much. It honestly is still a very successful layout and easy to navigate. The Turret coverage arcs are not terrible the pilots view is decent. The torpedo rooms seem huge and inside seem to be a bit of wasted space but the hallways around them feel perfectly claustrophobic, in fact the whole ship has that feeling and its perfect.
I agree, it doesn't need a total rework. They just need to think about a couple things from 2015 that were ok back then, but now with more larger ships need to be re-thought, like, a) can we put a couple more torpedoes in it, and b) can we reduce the crew needed, and keep it armored & protected).
The thing that kills the Retaliator is that you supposedly need 7 people to fully crew it. In 2015 that was ok, but oday, if I had 7 people in my party, I'd put one in the pilot seat of the Retaliator, and the other 6 in a Hammerhead. Fuck yeah!
I think most people would just be happy with being able to carry a couple more torpedoes, and have fewer but more powerful turrets, maybe even a couple of remote turrets that could be AI controlled. The latest iteration of the Retaliator in the 3.3 PTU actually has 3 Turrets with Size 3 guns, so that is a start. Now, if only the turrets a) worked and b) you could hit anything.