Thanks for the feedback!
Yes the turrets here are enviromental decorations with a touch of lethality. The Manager does tell you to not damage the prison's infrastructure, which includes them. I'll still add a text warning to save players a few trips back to the dock.
I'll also replace the Landing Pad on the Store room to a Docking Bay that'll let you swap ships after purchasing. I believe there was a reason I didn't do it already, but I forgot what it was. Unless I'm reminded of it, there should be no problems to implement this change.