First off: welcome to the thread!
I'll discuss some of your ideas (and hope others will jump in as well), but not all as I'm currently mostly concerned about practical implementation, so I'm limiting myself to those aspects.
That's basically already the case. However, I don't think I can really agree with your offense=defense approach. In Civ2 there was the ADH (attack-defense-hitpoints) system, which has been simplified in Civ4 to basically 1 value (combat strength), although promotions can still increase offense, defense or strength in general.
I'm skipping your remarks on ships systems (the more advanced systems like Quantum Detonator, Black Hole Generator, Stellar Converter, Hard Shields, etc. still need to be implemented...), racial traits and including actual Marines, because I generally agree with this.
This, basically, comes back to the offence=defense stance you're taking. In Star Trek for example, a ship's energy can be diverted to different ship systems (life support, propulsion, shields, weapons systems), which basically explains why offence doesn't equal defense: if all energy is diverted to shields for instance, weapons are useless. (If shields are down or damaged, they need recharging time: this doesn't effect offense, but does effect defense.) Unfortunately in Civ4 the weapons-armor-shield definition of MOO2 can hardly be replicated. (In MOO2, if armor=zero, the ship is destroyed; in Civ4 a ship is destroyed if overall strength=zero. Obviously, the MOO2 combat mechanic is more sophisticated...)
These ideas I like in particular! (They also look like the most practical to implement.)
Alright, now I'm back to work. (I'm currently making a list of Moo2 Civpedia/tech quotes to be included, which due the amount of time required probably won't make it into Patch4, but a list of what is in will be included.)
Once again, any practical help is appreciated!
I'll discuss some of your ideas (and hope others will jump in as well), but not all as I'm currently mostly concerned about practical implementation, so I'm limiting myself to those aspects.
So in the civ combat system defencive equipment really should effect offence the same. That would be boring though if every promotion just added a percentage bonus to all combat then there would be no difference between taking a weapon promotion or a shield or armour promotion. So I'd have to think in terms of what different effect a weapon or system would have when the unit is advancing vs. when it's stationary.
To get the customization of your ships feel of MOO. I'd have most equipment and weapons be promotions for units. The unit themselves I was thinking would be available with a new engine technology combined with either a new armour type. A new power source and stronger hull material seems like good prerequisites for a new ship model. It's probably best to still have carriers, missile ships, and transports rather than promotions that give them those abilities.
That's basically already the case. However, I don't think I can really agree with your offense=defense approach. In Civ2 there was the ADH (attack-defense-hitpoints) system, which has been simplified in Civ4 to basically 1 value (combat strength), although promotions can still increase offense, defense or strength in general.
I'm skipping your remarks on ships systems (the more advanced systems like Quantum Detonator, Black Hole Generator, Stellar Converter, Hard Shields, etc. still need to be implemented...), racial traits and including actual Marines, because I generally agree with this.
Shields I thought would be difficult. I've already gone over why defencing systems having no effect when you attack didn't work for me, but I though about it and in this case it might! You might remember in MoO2 if you didn't move a ship it recharged it shields faster. So the ship that is charging in to attack would have weaker shields. So while it should increase strength overall, it should also have a defence bonus. I'd also give each shield a first strike chance, the reasoning being that superior shields gives you the chance to do damage without taking any and that's exactly what first strikes do. Remember how shields didn't work in nebula in MOO? Well having all enhancements from shields have a disadvantage in nebula that cancels them out. Except for first strikes because I don't think you can remove them do that. Hard shields would add some of the nebula strength back along with standard shield enhancements. Shield capacitors increased recharge rate so they should probably even out the offencive abilities of shields.
This, basically, comes back to the offence=defense stance you're taking. In Star Trek for example, a ship's energy can be diverted to different ship systems (life support, propulsion, shields, weapons systems), which basically explains why offence doesn't equal defense: if all energy is diverted to shields for instance, weapons are useless. (If shields are down or damaged, they need recharging time: this doesn't effect offense, but does effect defense.) Unfortunately in Civ4 the weapons-armor-shield definition of MOO2 can hardly be replicated. (In MOO2, if armor=zero, the ship is destroyed; in Civ4 a ship is destroyed if overall strength=zero. Obviously, the MOO2 combat mechanic is more sophisticated...)
If you steal anything from Fall from Heaven it should be the unit capturing mechanic. People loved that in MOO2. Also it would give something for the particle weapons to do if there is nothing else do make them different. Achilles targeting unit, tractor beam, transporters, troop pods, could all add chance to capture a defeated unit. Then you could let any ship "lightbulb" technology like great people can. They could only lightbulb the tech that is needed to build them so it wouldn't be useful for the player that builds the ship, but if you capture one you can't build you could scrap and reverse engineer it to get new technology. That could also be a way to get Antarian technology.
The Quantum detonators effect could be implemented by using the code for Pyre Zombies from Fall from Heaven, but it's probably not worth the effort.
Time warp facilitator would be the same as the blitz promotion.
Subspace teleporters would work great using the paradrop mechanic.
These ideas I like in particular! (They also look like the most practical to implement.)
Alright, now I'm back to work. (I'm currently making a list of Moo2 Civpedia/tech quotes to be included, which due the amount of time required probably won't make it into Patch4, but a list of what is in will be included.)
Once again, any practical help is appreciated!