I quite like these ideas, though I'd say have the constructors clear only when not building stuff.

Yeah, sth needs to be done about those mines.

Good idea about reprogramming mines... nice (has sth evil to it: "Hey, the mine which destroyes my level 10 Marza was once placed by me...!").

I would prefer something like a mine control center. Each mine control center can sustain 10 mines. Every grav well can handle up to 10 mine control centers. Those centers can only be detected by scouts. Once a control center has been destoyed, the mines it controled will explode, too. No mine spamming anymore and a just conquered grav well can be cleaned in a reasonable amount of time.(Hm, Advent could just take those mine control centers over, once their scouts have detected them...? Hehe...).

And in my perfect little world, those mine control centers could also function as long range detectors for star bases: if there is a star base with long range weaponry in the same grav well, it can utilize the centers and shoot into their mine deploy range if an enemy ship happens to fly into it... (like scouts, who don't trigger mines...)

1. I think that mines should be destroyable.  They should still detonate when destroyed but their range should be large enough so that only LRM/cap ship/carrier would be able to hit them without suffering injury.The explosions from mines should damage(50% per hit) or destroy other mines which could make for some cool chain reaction type strategies and stops people from piling up mines in one spot since destroying one will destroy them all making this a Costly mistake for TEC users or at least a waste of time for vas and adv.  This will get rid of the 10 hour removal of a cluster of mines. Putiin alot together wont be totally useless however since a bunch of cloaked mines clustered together could still take out a fleet. This means you have a choice of strategies to use.Go for the kill with a cluster that might be easily destroyed or spread them out to do more gradual damage to a fleet but have less of a chance to have all the mines discovered and destroyed.  Scouts and mine laying ships should autouncloak mines when the are in attack range. (TEC droppods should show the number of mines in a well but not expose them)Once detected they are always visible to you.(This will let you use a scout independently like they were intended instead of in a fleet. These 2 types of ships should still be able to remove the mine without detonating it.  Also planetery defenses and starbases should be able to detect mines that are within the same GW.

2.  Mines should have their own unit supply points. It should jump by either 10 or 15 point intervals per upgrade. The number should be upgraded with the capship supply making the high cost of these upgrades more worth it.  also the vasari whould get a boost to this with their communications fleet supply upgrade.(same percentage as the current upgrade)

3. tec should get a researchable upgrade the boosts the damage. vasari gets the extra supply upgrade. advent gets a range boost upgrade. 

4.  Lastly the cooldown time should be made longer for the races that can get them for free.