Indeed, Sins mechanics are more based on 17-19th century warfare with standing infantry formations than modern naval battles. I imagine that is because its easier to simulate, thus they could make the game on a bigger scale than otherwise.

And yes, in fact that mod has already been made, though it has not been updated for Rebellion. That said, it really doesn't work very well for Vanilla sins units because dynamic combat was not in mind when they were designed. Flak frigates, capital ships and titans are the only ships in the game that can fire in directions other than forward. In practice, making ships use dynamic movement lowers there damage because it takes longer to loop around and face the enemy forward again takes longer than the weapon cooldown time. This was even the case in vanilla sins with strikecraft, where if you set them to "hold position" in front of an enemy they would do more damage (I believe this is no longer possible). You'd need ships capable of firing in multiple directions for dynamic combat to be useful.

The other thing that could make it worthwhile, that moving faster reduces the accuracy of enemy shots, is also not possible. There is no true dodging in sins, and there is no mechanic to turn speed into damage reduction.

It isn't hard to stop yourself relative to a certain point especially with the technology in Sins. You could do that to day.

You still be moving at very high speeds but motion is all relative.

Also objects don't move that crazily fast compared to others in space like fighter jets down at Earth.

While first off, gameplay does always need to trump lore, I would contest the assertion that ships should be constantly moving thematically speaking.

Ships move with relatively high apparent mobility(speed & maneuverability) because the game wouldn't be playable otherwise.  People seem to forget that even frigates are actually fairly big ships(crews of several hundred at least).

Even frigates by and large fall under the category of "large ships" that in most sci-fi more or less sit(their engines are usually running, but their cruising speed is negligible compared to the scale of the battle) still while fighters do most of actual movement.

Moreover they are not really of the scale where they would realistically have the mobility to make hitting them with weapons difficult.  And frankly if you're not avoiding enemy fire by keeping moving, much of the insentive to be constantly moving is gone- at which point you may as well use that engine power for something more useful to comat(such as more power to weapons, shields, or subsystems).

I honestly think that just because they are the "smallest" non-strikecraft ships, people forget that frigates are actually pretty big. Corvettes and Strikecraft are the only real thematically small agile ships in the game- and they happen to also be the only ships that don't sit still while firing.

the only ships that i would think should stop on its tracks while attacking are any capital ships or other bigger ships such as titans. frigates in the other hand should have a minimal pulse speed. e.g. in chase formation or engage maneuvers to hostile targets. if this would to happen at all then we'd expect to see light frigates, flaks, lrms, illums and other frigates or cruisers alike doing barrel rolls whilst capital ships making hard turn bank while in motion. these type of maneuvers are not a bad idea to make. seeming a real life like ship animation movements. i think it would be awesome.

Then you voted to have George W. Bush a president. Looks like series of great decisions.

We could be living on a banana FFS.

There weren't hundreds of them in multiple wells as this game.

Plus I'm thinking the projectiles are moving faster than the ships themselves, so movement would be pointless.

Not that it wouldn't be cool ........

The only things that really had dynamic movement were the fighters and corvettes like this game.

Frigates and above moved practically as slow as the frigates and capital ships here. Just they had the 3D aspect to the whole thing.

In Homeworld, HW2, and Haegemonia do use the same mechanic.Only the fighters, and corvettes constantly moved while the frigates, and cap ships came to a screeching halt to fight. Much like how Sins ships behave. However in Sins it stands out more because there are more cap ships, and frigates than fighters seen on the maps.

I believe it is this way for performance reasons. However it may also have been done to make the game "fun". I understand many want "real physics" in their games, but how fun would that be to a person that has no clue what newtons law is, or that isnt big on science. In other words they didnt want to "over complicate" it. Hence "easy to learn, hard to master".

If you really want dynamic movement there are mods for it. Maybe not for rebellion yet, but i'm sure someone will conjur up one soon. Like Goafan said weapons will have to be changed to compensate for the 360 degree dynamic movement.