my 2 cents:
You've mentioned "old school bombers" - they are really useless. You've mentioned "strike crafts". I think they are ok.
But imagine that you are designing a "capital ship killer". What do you want from it? I would want it to be
- extremly fast
- maneuverable
- undetectable
- very well armed
(well shielded - but in reallity no one expects the craft to be hit - except A-10/Su-25)
Sounds too "super"? No it does not. Everyone want's that. The only problem is that you cannot get all of this for reasonable price (at last in real world)
In X3 the "undetectable" is problematic so forget it.
So I think that we have 2 different approaches here which are probably most accurately represeted by:
A-10 - well armored, slow moving, very well maneuverable aircraft with (mostly) single purpose weapons. That's close to what are you describing above imho.
B-1 - very fast aricraft which relies on its ability to fly undetected in low altitudes at high speeds and then launch it's missiles/bombs.
I like the second more because you can make the ship/craft fast but not too maneuverable (thus preventing it from anti-fighter role) with some heavy weapons. the question is whether quick ship can avoid the capital ship fire in x3.
If you want projectice based weapons, then you can look at
Ju-87 Stuka or
Il-2 Sturmovnik or
Mosquito (anti-ship version) or the howitzer used at
AC-130.
All those planes used large caliber anti-material weapons.
Projectile based weapon used in space can be probably based on iron slug accelerated by electromagnetic means to some insane speed. Of course the same princip could be used to stop such bullet. Another approach would be to use non-magnetic material (such as titatium), but this material is light and it had to be accelerated by other means.
Note that the weapon should have a corresponding caliber-to-ship-size ratio. You cannot fire 50mm projectiles to 1000m length ship and hope to succeed (unless the energy would be really great, but even then the damage would probably be only "local").
The main problem with "designing" anti-capital ship craft is, that in "real" space, such ship would be invincible. Look at todays carriers or missile cruisers. They have 2 major weak spots:
- They cannot watch under water (not too well)
- they ability to detect flying targets is limited at low levels (near ground)
- another weak spot is that the anti-missile systems have short range and thus they have a little time to react to incoming threat. I think that Phalanx based CIWS cannot destroy more than 2 missiles simultaneously - its "operational window" is from 1 to 2 seconds (Goalkeeper is probably better as it is using
GAU-8 )
But space-based capital ship would not have any of these limtations. It would have enough power to supply its LONG range sensors. There would probably be no range limit for the CIWS as well. Of course there is no direction so no underwater suprises or dive-bombing.
Truth is that X series never care about "reality" but there must be some quide lines - some limits. If no one else then we have to make them in order to make some good mods.
Anyway, someone should first test whether adding another "mass driver" is possible othervise this talk is lost of time