Increasing battleship speed will have zero effect against a fighter at the speed change I propose. It will just make it easier to navigate..... some of the ships are so problematic that you really don't want to move them anywhere. The Rheinland battleship as well as the kusari can't use tradelanes most of the time. The Rheinland behemoth also has problems docking with jump gates, but more of last patch than this one.
Kane right now battleship weapons have zero weapon power required to shoot them.... you can stick them on fighters. It looks funny except for the cruiser forward gun which has no graphic.
As for the gunboat guns, maybe just up the power cost by a lot and leave the damage as is?
I also agree that the coded level 10 guns could use a boost maybe..... Honestly though 4 nomads are probably better with 2 level 9 guns that require energy.