Hi! A few comments:
You say you want "more strategy, more epic feel" - how does overhauling the combat system (again) provide that? As Yavrin said:
I personally think that it may be possible to apply to CG2 with minimal alteration to AI, seing as it only really affects combat. Some of these ideas I have raised before but here are my thoughts..
As such, I don't think this is really an important change. If GalCiv III has any form of tactical combat (not to say I want it to - the lack of tactical combat is a nice difference between GalCiv II and most other 4x space games) then I would obviously consider changes to the combat system important. Right now, though, I'm not sure why so many people keep wanting to alter it. Except for aspects such as the eventual pointlessness of defenses - which may not happen in all games anyway - I think the current system works well enough.
Also:
Well, what i would prefer when it comes to weapons and defenses is that the different weapons are there, but they ALL need to go through shields, the armour you have lowers the damage to the hp or something like that, i would honestly prefer that.
This is fairly unlikely to occur in GalCiv III. The current combat system has all three weapon types as having the same effects in combat, and if combat remains in its current form as simply a dramatization of a series of die rolls, I don't see why it would be necessary to change that.
Sorry if this comes across as overly antagonistic... I just feel, whenever anyone proposes some neat new combat feature (carriers, stealth, ramming, boarding, etc, etc.) that without some form of tactical combat there's no real need for it.
All this said, one thing I do agree with:
the above example alone add lot stratgic depth while keeping things simple, you obvoiusly be want ships with the uber weapons to quickly take out any heavily armoured capital ships, and you also want to have some ships with LOTS of weak gun for dealing with fighter fleets or unarmoured targets
I would like it a lot if the game provided a good deal more distinction between hull sizes, and also that both "small" and "large" ship strategies were equally valid. Right now, it seems that fighters in the late game are fairly useless.