this is the veteran player vs new player dilemma - while you perceive the turrets as slow, clunky, and almost not a threat, this is not the case with someone not yet aware how to handle them properly. a good example is the security checkpoint at the end of eng1 - veteran players will have little trouble dealing with the turrets there, but new players will struggle a lot, and I mean a LOT.
so no, there are no plans to make the turrets harder in the main branch.
Those particular turrets are both already facing in the players direction when they enter the room, which is part of the reason why they are so deadly - turrets can shoot almost instantly after opening if they are already facing you. Increasing the turn rate doesn't make them any harder, it only makes the easily cheesable ones a bit harder, and prevents circlestrafing. Veterans are often going to be circling around turrets hitting them with a wrench, which is made harder by increasing their turn rate, which doesn't affect newer players at all. This makes the super easy joke turrets a bit harder, without affecting the already difficult ones.
yup, that bit probably should be visible from the cargo bay too. I'm guessing annoying brush work would have to be involved to make it happen.
Making it technically happen is quite easy, since the two rooms are directly on top of each other, so I just deleted the bottom one and extended the top one down. The problem is it doesn't look particularly great...
Although I think most of the problem can probably be solved with minor brush work, mainly stretching out some things and adding a few vertical sections around the sides to make it look less like a flat plane.