I'm liking a lot of the recent suggestions made here.
Re. conversation about how mines might specialize in the production of desired minerals:
I am a big "yes, please" for any revision to mining that allows us to fully appreciate quality mining sites that don't include the full suite of scarce TN resources. I am also a big supporter for changes that ease the pain on resource-reliant AI entities (if any), and/or that make multi-faction games more competitive. If the player requests such a game, then there simply must be enough adequate resource sites, in reasonable range, to give more than one empire a fair shot. Letting Gallium 0.8, Duranium 0.0 worlds specialize would therefore be a big, big win.
Re. fleshing out pre-TN gameplay a bit:
Aurora allows players to choose pre-TN starts, but doesn't really deliver much to do in such games except to develop a single world. The problem is more than that it's so tedious to get anywhere with pre-TN tech, it's that there are almost no resources that would make you want to bother. I feel that Aurora would do well to "fish or cut bait" here: If pre-TN is retained, let it deliver a bit more gameplay. If this is not desired, remove it.
I lean towards removal, because of the lack of any physics required to support Newtonian (or Einsteinian) -constrained motion. Because bothering with these is just not what TN Aurora's all about, worrying about pre-TN ships and movement would be a major distraction, not merely at the coding level, but at the game design level. The question has to be asked: At what point do we need to simply "let Aurora be Aurora"?
Re. Ship and military concepts:
I like the afterburner idea.
Fleshing out armor and allowing different types sounds like it could add a bunch to the gameplay. I really liked Star Ruler I and Star Ruler II's take on all this.
I quite take mtm84's point that the way armor is actually calculated is needlessly opaque. It /might/ even be mathematically incorrect, perhaps due to iterative calculations on rounded results. I don't know. All I know is that armor is weird. Better, like he says, to calculate the volume of a shell with a specified thickness, and then round to an even number of armor boxes only once.
The easiest way to translate this result to the armor box that Aurora currently uses is to divide the non-rounded armor volume by the number of armor rows, then round the result. If this leads to armor calculations that jump around too much for armored small ships, then either increase the number of boxes per unit volume, or re-think how armor is damaged.
I'd love CIWS systems that weren't so big. Like Jordan_CAB, however, I do worry about them potentially getting overpowered. One straightforward way to balance them is to remember that, in the real world, the effectiveness of CIWS is not linear with their number. The first such system protects better then CIWS # 10, regardless of the weight of incoming. Among the reasons for this is that it is much easier to optimize integrated fire control and weapon systems LOS/LOF relative to incoming heat for one system, than it is for multiple, each having their own LOS/LOF, and each having to coordinate with all others ... or just overkill some missiles and miss others.
SM option for creating mining colonies:
Solid idea. Off-world mining, transport, and the civilian sector are often critical parts of the backstory.