Well, Useless and Flavour are not at all the same thing in my understanding, and one of my goals in this new traits is actually to make "flavour" traits.
What a Flavour trait is in my opinion is a trait that doesn't drive the player's strategy, that maybe doesn't matter that much except in some situations or aspects of the game, without ever being unbalancing, and of course that hints at other possibilities than usual gameplay, even if they won't necessarily manifest in each game.
You will, I guess, never triumph against your enemy just because you have Acirema warships, yet it does makes a difference to have this small shield bonus, and in some (though rare) situations it may mean the difference between victory and defeat.
If, in a single battle of a whole game, having +10 speed allows a manoeuvre that would not have been possible without this bonus, then my goal is achieved : we have a trait that gives some flavour to a Species, that makes it sometime plays slightly differently, but which is not useless.
Not that I'm against bigger traits, but I don't believe that my mastery of the game is sufficient to balance them correctly.