One thing about the Defiant, or any spaceship stats in general: shouldn't there be a class element to FTL travel? I mean, I guess you can just have an engineering feat to overcome any "we can't get there fast enough" situation (judging by Scottie and Geordi), but it seems like there should be a 1-pt. "good" FTL and a 2-pt. "superior" FTL or something.
If you want to have an especially good FTL you could spend more points to upgrade some trait of the system: like Good cruise range or Fair power efficiency.
However it's easiest and sufficient to assume the average of what we see in trek: ships go warp 1 to 9, higher numbers are exponentially faster than lower, and you start to strain if higher than 9 - where you'll need that Engineering check. Outside of Voyager we never see significantly faster ships than this standard, because it doesn't matter unless a central theme of your story is "Gotta get home before we die of old age."