After a couple more sessions I have a few more questions about space combat that have came up :
1- is it possible to trade attack dice for damage dice 2 for 1 in space combat as per normal combat ?
Absolutely! Attacks are resolved in the same way as regular combat.
2- is there any effect for a critical (triple-6) during spaceship combat ?
So - as written - yes; technically you could inflict a status on a starship. That said, the only damage types from starship weapons at present are heat, radiation, ballistic, and ion, and tired or nauseous ship doesn't make much sense (though one on fire or bleeding/leaking does). There needs to be some language adjustment. I didn't plan to include crits in the starship combat rules, and save them for an advanced article, but for now yes, you can use them, but you may have to change some words and descriptions to make them make sense!
3- Are ion weapons stopped by shielding and/or armor or does it bypass them ?
They are described in detail in the Starship Construction Manual -- shields only get half SOAK against them, and any damage that gets through is applied directly to CPU not to SS.
4- if e-warfare defense is 1/2 CPU does it go down if you lose CPU due to ion attacks or e-warfare or does it stay constant ?
It stays constant. Note that the minimum value of a DEFENSE is always 10, also.
5- can the same action be taken multiple time, such as repair, to gain back more than 2 points of Super structure or is it limited to once ?
Yup. You can divert all crew to emergency repairs if you need to.
6- page 3:26 mention that a repair action can get back 2 CPU. However the starship construction manual p.18 states that "reduced CPU is automatically restored at the rate of one point per turn per size category of the computer. Firstly is the size category of the computer the same as the ship ? And how do these two rules reconcile ? Does a class VIII ship recover 8 CPU cycle automatically and then 2 more if a repair action is attempted. And if so doesnt that make ion attacks and e-warfare rather pointless as it will regenerate faster than it can ever be taken out ?
On larger ships, yes, it regenerates pretty fast. Those ships have multiple redundancies, all sorts of stuff - it's substantially more difficult to drop an EMP on a carrier and knock it out, and even if you did, you might only get a round or two out of it unless the EMP was *really* big! You'd need to do more CPU damage than the ship class, basically - on a Class VIII ship, you would need to be doing more than 8 CPU damage to start having any useful effect. There are larger weapons which can do that easily - the GIC-1 does 5d6 ion damage, as does the EIP-1, ; the LIC-1 does 3d6. And if you trade some attack dice for damage dice, that starts to get quite painful for the target.
You are correct in that the extra 2 CPU is on top of the automatic recovery. On a small ship, that can matter. Imagine R-2 fixing the Millennium Falcon -- it's a Class I ship, only recovers 1 MP per turn. If you can do more than 1 MP damage to it in any given turn, then it's going to be hurting.