One thing that really bugs me about sins is the lack of formations for your fleet. With the new graphics update in rebellion, zooming in on your ships is pretty neat. However, zooming in on a fleet, seeing these well designed, shadowed, and gorgeous ships parked in complete disarray should be fixed.
Furthermore, I would like to see different formations for the individual fleets.
Heavy frigates and offensive capital ships in the center, with light frigates and other capitals on the flanks (Slightly forward of the center), with the long range and support frigates bringing up the rear.
How about a simple column (think being able to punch through a minefield in a line with your cannon fodder frigates taking the brunt of the damage)
maybe a defensive wall; offensive frigates and offensive capital ships in a wall (both horizontal and vertical) in front of support frigates and capital ships