I don't know if this idea has already existed but I would like to see more ship stats like:

* Acceleration
* Max Engine Size

and

* Max Battery Size

I don't know if this will be a lot of hard work for the developers to add more detailed stats to the ship.

but heres the new example for the ship stats:

Itani Valkyrie

Advanced Fighter
Weapons: 3 Small
Agility: High
Acceleration: Very High
Max Engine Size: 2(Which would be efficent engine is the max engine they can only hold)
Max Battery Size: 3(Fast and Heavy battery are pretty much the same port size)
Length: 12m
Armor: 10000/10000
Cargo: 0/4

The max battery size and engine would require equiment to have size included. Just like the Small and Large ports with the Guns.

(S) Ion Blaster
(L) Gatlink Cannon

would be like this:
(1)Light Engine
(2)Efficient Engine
(3)Medium Engine
(4)Heavy Engine

(1)Light Battery
(2)Medium Battery
(3)Heavy Battery
(3)Fast Charge Battery

good idea? bad idea?

Limiting the engines ships can equip is basically the same thing as limiting their agility. Which puts us on the track towards greater homogeneity in ship agilities. Which, I think most of us decided, is a bad thing.

No, limiting the engine and battery sizes is not a good idea. At least not with the current choices for batteries and engines. Currently its set up so you can choose between having power and speed, or going a long ways on your battery. And the batteries are set up so you either go forever on turbo, running away, or you get a battery capable of firing a lot of shots without a recharge.

Current choices seem to be good enough for diversity.