I've played through a couple large Entrenchment games now, and I figured I might as well put my two cents in on the Mine issue.
I like mines. I really do; between them and starbases, it REALLY helps slow the game down in a good way. In the vanilla game, I always played the Vasari because the other races simply couldn't react quickly enough to reinforce an attacked world before it was destroyed, but with these additions, chokepoint systems can finally be defended heavily enough to hold out for a bit. But on the reverse side, once I filled out my fleets in the vanilla game, they were unstoppable; a fleet of three capital ships (space egg + carrier + (battleship or ground attack)), five carrier cruisers, and ten heavy cruisers could roll through the defenses of any enemy system that didn't have a standing fleet, and in the later game I'd add another five carriers and five heavy cruisers to each. I had four of those fleets, plus my "primary" fleet of the remaining 4 capships (egg+carrier+ two devastators) and 15-20 carriers, plus an assortment of utility cruisers. Five fleets, any one of which could handle any typical planet without ANY losses, and I'd only need to link two of them up when I confronted the enemy's main fleet. Games went very quickly, because I'd quickly cross the threshold of "mopping up".
With Entrenchment, I actually had to hold up some of my advances long enough to get TWO of those fleets into each system. Mines would chip away at my cruisers, losing a handful of them per system, and the starbase could hold off the capships for far too long. It was a good thing.
But I'd still change how mines are handled. Here's what I'd like to see:
> All capships should be able to engage mines directly, at the range of the current scouts (i.e., short). A capship moving through a minefield should be able to clear its own path as it goes, unless the field is REALLY dense. This still has a combat value, as the capship will be using its weapons to engage mines instead of defending itself from other attacks. And this wouldn't have to extend to its accompanying frigates/cruisers: scouts would pull mines to where ANY ship could engage them, while capships would just always be treated as if there were a scout within their range. This ability could require a general research upgrade to unlock, but it shouldn't be that high of a tier.
> At least one other ship type for each race should act like scouts do, with their current range. I'd vote for one of the "specialty" cruiser classes (for the Vasari, I'd say the Overseer, since it's all about detection). That way, heavier fleets wouldn't need to bring a half-dozen incredibly vulnerable scouts along. This ability should require a high-tier research upgrade to unlock, which is fine since these ships themselves are high-tier.
> The detection range on the dedicated scout frigates needs to be at least doubled over its current value. You shouldn't need to have five or six scout vessels per fleet just to ensure quick targeting of mines, and this would allow the scouts to remain useful even after the above change. This could be a researched ability (starting out scouts would have their existing range, but you can increase it), probably mid-tier.
> Starbases should be counted as being scouts for the purposes of mines. That is, they should have a large detection radius and be capable of pulling the mines to where they can be engaged. This should be automatic.
> Scouts should get a "Minesweeper" AI toggle, sort of like the current "Explore" mode: with it on, the scouts will attempt to move towards any mines in the current system to spot them for other ships to clear. Plus, they'll use their own dinky gun to kill the mines as well. This AI should probably be the default; a scout without player-given orders should head towards enemy mines automatically.
> Owned planets should automatically detect any mines in the gravity well, for that system's owner. That is, once you control a system, the system defense structures (hangars, starbases, etc.) should be able to clear any enemy mines without user input. This still leaves an offensive use for mines while attacking an enemy system, in that it creates more things for the defenses to engage, but it doesn't affect them when mines are used as a defensive tool. Too often, I ended a game with hundreds of enemy mines still around my systems, leftovers of long-dead civilizations. This ability should require a researched upgrade, although I'd say it could even be a side-benefit of one of the Artifacts.
> Minelayers should get a "Wander" AI toggle, like the modes mentioned above. With it on, the minelaying ship should meander around the current gravity well, dropping mines as it goes, without user input. I was having to lay down a dozen zigzagging waypoints for my minelayers, and it got tiresome after the first few systems.
> Mines should, in general, be more powerful and more expensive, so that you don't need to place so many in a system. Take the Vasari as an example; they currently research a mine upgrade that lets them lay mines that limit movement, in addition to the default explosive mines. This should instead be an upgrade to their existing mine, not two separate activated abilities on the minelayer ship, and would retroactively improve any mines belonging to that player. Mines should also do damage in a considerably larger AoE, although this could vary by race: TEC mines might have a big AoE and a large trigger radius, Vasari would have small AoE but high damage, and Advent would be "directional" (pick a single target within a small proximity range and do all of the damage to that target). Also, cleared mines should have a chance of triggering as they go, possibly damaging the ship clearing them.
Bottom line, frigates and cruisers that aren't accompanied by scouts should get ripped apart by minefields, but primary fleets (ones with capships) should be able to handle them better than that, especially if they also have scouts. Mines would still be tremendously useful, in that you can still fortify chokepoint systems well enough to keep the random one-frigate scouting parties from charging through and slow down incoming battlefleets long enough to reinforce the system, but they wouldn't be the micromanagement headache they are currently.