The idea of getting to shoot at the end of the attack phase with a turret equipped on the Phantom makes perfect sense. You get to shoot out the rear arc because the phantom is facing that way (should be 3 die out the rear though) so it makes sense that the phantom is making the extra attack.
For those saying get good against the Ghost, well yeah it has 0 agility, but Fenn strips one ships focus, and can prevent another from spending. Combined with sensor jammer and an evade token, that is 3 auto(unless expertise) evades a round. While pushing out 4+damage a round, it's easy to see how it's hard to counter.
As for TLT in general, giving defensive range 3 bonus against all turrets is an easy fix, and it will only impact TLTs at the moment.
I think making Miranda's ability primary only is too heavy handed. Can she be FAQ'd to have her ability impact both shots of the TLT? I'm not sure if this specifically is against the timing chart, but it would make her way less reliable when regenerating. You would also have to declare her ability before rolling the first attack. Combine that with the TLT range bonus, this should make Miranda a little easier to deal with. (she's already not as bad since the advanced slam fix).