Firstly... using "ALL CAPS" does not enhance your argument. It emphasizes, but does not clarify. Or rather, it clarifies your emotional state, not, your ideas. Since your emotional state is irrelevant as to whether your ideas have merit... it doesn't really assist you. I resort to all caps on occasion, many of us do, but I also recognize it for what it is... a vice, not a virtue. I highly recommend that people use said vice sparingly... at this point (JJ) your usage is so frequent, it is actually detracting from your points.
Secondly. Space mines are no different than say... orbital defense platforms, or any of a myriad possible ways of passively defending a planet or location. Space mines as a specific idea though... are generally not favored by people as a "Sensible" concept because space is truly vast and it is presumed that most mine fields would not be mobile.
But JJ, your concept has some merit... it would be nice if we had a passive and powerful method for defending our colonies other than ships..... which in my opinion is what Starbases ought to be able to do. However, its largely irrelevant... a minefield... starbase... or a ship... they all get built by production... it just a matter of how much of that production got spent on an engine.
So you could easily build a spaceship with no engines, fill it with weapons, shove it in orbit... and there you go... you have your minefield.
Thirdly, I think Hypergates will be cool, and instantaneous travel for them would probably just be too good... maybe VERY late game? Also perhaps we will get lucky and the Hypergate speed will be scaled by map size. Personally I'd love to see Hypergates be a type of Starbase, complete with upgrades for them, including speed boosts, defenses, etc. If anything perhaps they should replace military Starbases because such an important piece of infrastructure is well worth building into a fortress... it is afterall the most likely place where friendly reinforcements can come from and therefore would be held at all costs.
Fourthly, I think the whole debate about "What players want" is hilarious because none of us has any data about that. I can remember players unloading a lot of hate about the tech tree and its different mutually exclusive technologies... there was a pretty successful and popular mod that got rid of those for quite some time. It doesn't make any sense for technology to be mutually exclusive ... learning how to make ships have more HP does not stop me from learning how to build those ships more efficiently. What could be mutually exclusive is execution... perhaps I cannot apply what I learned about making ships with more HP and keep them efficient to build... but once I've learned both I would have the choice to apply one or the other, as needed. This does not happen... for the most part "learning" and "applying" have been integrated making this choice difficult to realize in-game. Ship components can be an exception to this notably, as can structures.
Ideas that don't make much sense automatically get a down-vote for me, and they need to be very fun, exciting, or thematic to make up for it. This feature is not particularly fun or thematic and so I look forward to it disappearing.
Fifthly, I find it funny how GalCiv treats population and production, and people have made some very good points about population and housing... but production... why does everyone assume more people = more production? It's not going to in real life for much longer (historically speaking) in my opinion. For example... the direct production of food could once be easily linked to the exact number of people farming... this isn't really the case any more, because tools, animal labor, automation, genetic engineering (better crops) continue to mess with this equation. Right now, you could consolidate every mass-farming institution in the mid-west United States into a single corporation, fund its automation, and drastically reduce the number of human beings involved in the process of making that food and I'd wager it'd be enough to feed the entire planet.
Military force too, has for most of human history been strongly linked to population scales... but again, technology weakens this link. Today we are the cusp of automating war to a degree not seen before, the United States is relying more and more on drones and less and less on pilots in a plane. One drone-pilot can manage multiple drones potentially, and very little stops us from fully automating such weapons. Perhaps unwisely to both our material and moral peril, but that hasn't ever really stopped us has it?
Population does not automatically = production anymore, or it won't in the future when far greater degrees of automation are available. Population can also be seen as a great liability... population's correlation with production is weakening, but its correlation with consumption is only increasing. Consumption leads to less reserves of important resources, greater strain on limited facilities, more people to police... China, both today and in its long history, has long had to spend an enormous amount of effort controlling and safeguarding its populace... historically speaking, it has been quite a rebellious place. The United States is eating/consuming far more than a fair allotment of the earth's resources and constantly fears upsets in global status quo as a result, making it vulnerable to relatively small events across the entire planet.
If people are not producers, but they are consumers... what purpose do they serve? Well don't worry, they still have some purpose and they still produce something, but I'd argue that they have limits to those things. A colony is likely weak if it only has a 1000 people, but it likely isn't gaining very much once it has a million or ten million people... or say a billion... at some point though, it's going to capsize from a boon to a burden. They don't perform much manual labor, intellectual labor is only so useful (how many "Einsteins per capita" do you realistically get, need, or can't simulate with AI?) and they eventually can start causing a significant drain on resources that could otherwise be spent on infrastructure, military strength, or important projects. Or they get so numerous they cause serious climate problems, political problems, or police problems.
The point is... not that I am perfectly "Right" or such, but that there is plenty of room to consider changing the formulas of population vs production based on these reasons. I'd make a case that colonies should have very low population, a certain flat rate of industrial development based on tech and what you send those people with. The population would still be the primary mover for generating wealth and research, so you still need them to grow.
This would then mean that we could have a very slow growing population (which arguably should be more vulnerable to bombardment, disease, random events, etc.)... still be able to create the level of industry we are used to as players, but suffer a research and economic penalty for going very wide very quickly. Super heavily populated planets should start suffering industrial decline as more and more resources go into keeping the consumers happy, and over-taxing the local resources should have climate/pollution impact. Mitigate these with racial traits and technologies as needed... but the real challenge isn't going to be "how do I get enough people" it is going to be "how do I control this many people... this far away, and how do I stop the locusts (people) from eating all the stuff I need to build to protect their sorry assess".
I think taking a deeper look at population in this way, could lead to a much more sensible set of game features for building Wide and building Tall. Tall empires would focus on that automation, limiting population and consumption, giving them more resources per planet to work with for building orbital constructs, ships, drone armies, Dyson spheres, etc. Wide empires would focus on technologies that allow them to claim more planets, further away, and faster.
The wide empire can win, if it successfully claims more territory and then survives long enough to develop that territory "tall" similar to how the game plays currently. The Tall empire wins, by staying small until it has achieved an advantage in tech and resources and decides to strike out and attack the wide empires when they are still vulnerable.
Talls still become Wides in the long run. That is unavoidable unless you allow for win conditions like "I achieved ascendancy and don't care about material life! Wooo" or "I researched winning!" or "I magically made everyone love me to death, they committed suicide to honor my glory and I win".
Ok... and you can have those in your game they can be thematic, but lets be clear... there is always "I won because I had the military strength and industrial production, technology, and happiness to avoid rebellions and exterminate my opponents directly or indirectly." AKA ... not a super-narrow arbitrary win condition. Domination.
I support introducing Tall strategies, not because they stay tall, but because they give a great variety in play style for the early to mid game... and they can represent a fun challenge (if done right) to those of us who play wide empires early on. Colony rushing is still going to be a thing, its just going to leave your empire more vulnerable to tall empires for a period of time while you catch up. That sounds like a fun challenge that can and should be explored.
Finally... none of that matters if they don't fix Ship Roles or Carriers, or Commanders, and other stuff, because I can always defeat the enemy ships... always. Galactic Civilization means very little if we do not have a working/kinda-fair model of its antithesis: