furthermore these ships display a remarkable lack of inertia if you consider that
a) they are in space so there's no gravity;
b) space is a vacuum so there's no drag, and
c) when you remove power from the thrusters... you actually stop.
Yeah.. inertia isn't very well thought out in the wing commander universe. like ever. especially not in the original games.
Having the craft actually stop forward movement when thrust is removed is one of the adaptations that would be necessary to make such craft practical in the first place. They need to be piloted by humans. Humans may be good at piloting craft in environments with friction and drag, but space is another animal. The less specialized those humans need to be in order to pilot the craft, the better. In terms of the Wing Commander universe and storyline, remember, the human race was on the losing end of a protracted war that would have thinned the ranks of the most highly specialized people adept at handling the physics of space, and they would have lacked the time and resources necessary to train new equally skilled pilots. Just as the Germans in World War II and various guerrilla wars have resorted to using children as soldiers, so too would the humans of the Wing Commander universe have needed to compromise who they accepted as pilots. The only way they could make that compromise and still be an effective force would be to modify the craft to suit less highly trained pilots. It would have been necessary to adapt the craft so that as many humans as possible could successfully pilot them. The adaptations would have included things like automatic reverse thrusters to counter the various inertial forces, both for forward motion as well as tangential. They're abstracted and hidden in the game mechanics precisely because they would have been an abstraction of the process if the craft and pilots were real. They would exist precisely so that the pilots didn't have to worry about those other forces in order to pilot effectively.
That is why it makes perfect sense that fighters stop when thrust is removed, and why they should also have more predictable turning behavior than they do right now. You see what I've done here? I've actually placed my reasoning in the context of the game universe.
Ooh, I like that explanation! And here I thought it was just so we didn't wind up with X5700: Mantis (if you're even wondering why space combat sims don't use Newtonian physics, try that game. It's a lovely demonstration of why you don't want that).
The Evochron series uses both inertia and WC style controls, switchable between the two at any time. IN fact you have to in order to conserve fuel, something that WC never really took into account. Hey... Play for the action and the story, not for the physics.