In an early post I speculated about "shields" as an acceptable technology; it prolongs space combat, gives the heroes more survivability, and also provides a way to justify otherwise pretty unreasonable engine exhaust velocities.
I have been re-reading the "defenses" page of Atomic Rockets and re-thinking that position. Whatever hand-wave we might want for the engine, keeping the weapons systems effective and dramatic is probably a pretty good idea. I have been reading sections of The Fighting at Jutland and I was impressed at how the most dramatic stories were those of the most damaged ships.
If there is a question, it is what are the most viable platforms? Large ships with extensive defenses or small craft, but many, with big-ship-killing weapons? I must think through my technological assumptions and come up with something that works for me.