Nice feedback, and well organized, worth the time to read through it.
I don't really agree with limiting the # of starbases to a fixed amount since it severely hampers their use as an entrenchment tool. (and people will be always scuttling the older ones to build new ones on the "front lines" As it is Star bases cost enough to upgraqde, that spamming one per grav well isn't cost effective in msot games, but can make for a viable defensive option if one's getting pushed back.
Doublign the number of star bases to 2 per grav well and upping their weapons ranges (for advent and TEC) to include 1/2 the grav well would fo a long way towards making them a solid defensive option. Fort the Vasari about 1/4 of the grav well for weapons range woudl be about right I think since they can move. (and a built in phase jump inhibitor is nearly a must)
Good call ont he torp ships, making them able to engage with a secondary weaon would solve a lot of the headaches designating targets to them. I;m not sure about the range being outside the bases weapon range if they get a range boost = to 1/2 the grav well or so.
Mines... Well I just find them to be a performance killer on large maps and would be happy with an option to turn them off before play (like one can with pirates) to solve that issue. Also maybe making them always bisable woudl work well? the purpose of a mine field is to block off and route an enemy, whcih cloaked mines don;t really do all the effectively. Making the mines targetable by fighters & bombers might help balance them out more, and giving them a limit on the amount of mines per grav well.