Just a thought that might add to the tactical aspect of the game:
"It's dangerous to go alone!" - with this in mind, a lot of teams play grouped up for the obvious benefits that come with that tactic (better support, easier for healers, etc.). There aren't really many downsides to grouping up in this way, besides risking everyone being hit at once by large radius weapons like nukes. Obviously you can currently damage yourself with nukes/missiles if they hit your own ship, but there isn't currently any friendly fire. Nor is there collision damage for that matter.
So I'd like to suggest a mode that includes both - where your weapons do equal damage to your allies as well as enemies, and with some collision damage - nothing too high though, but where it would obviously vary based on ships speeds and size, i.e. a corvette flying head first into a dreadnought is going to regret it, but likewise two dreadnoughts colliding at a snail's pace would do some damage, but nothing drastic.
This would mean players would have to be more careful with positioning when firing at the enemy, when getting close to heal others/be healed, and when racing about the map in light ships. It might also add an additional tactical element. For instance, a dreadnought that's about to get killed by a stationary light destroyer might be able to charge into it as a last ditch effort to take them down at the same time, or a corvette accidentally charging into a heavy destroyer due to a poorly executed Assault Blink Warp could prove fatal.
I'd suggest this be a specific game mode rather than default behaviour though, because some people may have gotten used to there being no friendly fire, and because sometimes it's nicer not to have to worry about details like that!