I would remind the reader to review the EVE lore and to carefully consider what place and perspective an EVE mod of Sins would take. Would a player be controlling an NPC empire, NPC corporation, or a pod-pilot-only corporation? What options should a player have open to them at that level of abstraction and with the chosen perspective? Is that possible in Sins? Is it APPROPRIATE for Sins? Would it be fun to play (after the first couple of games when the simple fact that you have EVE ships in an RTS wears off)?
I will personally argue that a player should be controlling an NPC empire. This would explain why there are leveling and non-leveling ships; near-immortal pod pilots gain experience, download skills over time, and customize their vessels whereas normal mortals man the navies' droves of cookie-cutter ships by the thousands. Control at an empire level would also fit the Sins lore. Control of a pod-pilot-only corporation would expect things like heavy customization, T3 access, and no need for planetary populations; this is unlikely to be achievable within Sins, or else it will require an amount of modding that will likely never see a day of completion. Control of an NPC corporation might work, but it would be awfully restrictive of the ships available (most corporations produce no ships, and those that do usually only produce 1-4 different models).
I would also suggest that, instead of being equippable modules (something that would be hard and complicated to achieve, and time-consuming to manage in-game), the different modules and their meta-named variants be used as the research tree. The skills necessary to equip them could be used to guide the tree-ness of the researches too.
EVE Online Tech-3 and subsystems do NOT fit into the Iron Engine and SoaSE. I think you could make a very fun mod eschewing T3 though.
As to custom-fitting different modules to different ships, that too does not fit into the Iron Engine or SoaSE. I also think that would destroy any attempts at balance. EVE Online proper is very poorly balanced as things stand already, but the random factor of each individual pilot's competentness is a balancing force in itself (and the fact that no one is forced to use a particular race's ships or equipment).
I think that both story-wise and gameplay-wise, an EVE mod of Sins would be much better off selecting pre-set loadouts for ships based on their EVE standard bonuses (so a ship with a bonus to medium energy turrets will fit medium energy turrets).
I think that another important aspect to consider is time and effort for the mod. I think it would be much better suited to doing a nice mod rather than an everything mod, because the nice mod has a chance of ever being finished before this game is long gone, dead, and forgotten about. AFTER a nice mod is complete and working bug-free, then additional niceties can be worked in. As such, despite whether or not they would be enjoyable to have in-game, I would first toss out supply trains, subsystems, aesthetics beyond ship models, pirate changes, major changes to gameplay mechanics, and UI changes.
- Supply is abstracted in Sins for a reason.
- Tons of customization choices are for turn-based games or tactical games with few units, not for epic real-time games with hundreds of units and nearly too much to micro-manage already.
- Additional aesthetics can come later.
- Alterations of pirates can be put in later. Also, it may be hard since the pirate faction texture coloring is hidden in some .blue and .red files that I have no clue how to read or extract.
- Major changes to the gameplay mechanics will either be hard-impossible because of hard-coded restrictions (look at the Star Trek mod and cloaking), or incredibly hard to balance properly because they will be new.
- Trying to mod in ammo, or ammo changes, seems like a bad idea. If you put it as researches, then there is no way to un-research something if it turns out it was a bad choice.
- Trying to mod in harvesting ships is probably not possible, at least not acting like they do in EVE.
- The Sins GUI works great and Sins players already know how to use it. IF this is ever done, it should be an optional additional component.
@ MajorStress: EVERY turret in EVE has a mesh, although a number of meshes share a common texture.