Shield Boost - Its ONLY use is when you find it early as part of a mission. It really needs to be a HULL boost, so it could have some conceivable use.
Escape Pod - Total trash.
Teleport - I use this early game with an Armada. Its fast cooldown lets me keep an EXACT range from the enemy... usually when I find 600-700 range ion mark 1 guns and/or lasers. I avoid their PD, dodge missiles and not get cheezed at long range. By the time you pick up a second ship, its useless. It probalby ought to work for the whole fleet.
Missiles - Human missiles and rockets are horrid. You only use missiles/rockets if you find some other race's where you can burstx3 them without their range going to crap and/or having to spend a fortune boosting range.
Tesla/Energy gatling - useless by the time you find it. Needs to be available on first map.
Flak Cannon - By the time you can get enough of them to justify a strategy, you generally are up against enemies that DO have them already. Which means you aren't countering them... you are just matching what they have. they arent readily buyable enough to try to use them early.
Bolter fighters are viable on HARD with the 2 bay carrier. Its a good way to get lots of fast firepower. They aren't great and get sold later, but they DO an excellent job of being large and soaking up damage.