How can you not kill the freighters? lack of time?
Just make sure that you sneak up on the defender and give him an alpha at range 5. This should pretty much kill him. If it doesn't, sick your shuttles on him, or finish him off the easy way.
The freighters take 1 shot apiece.
I'd examine your refit. Remember: The Hplas is your friend. Its all the romulans have that work well, so make sure you have 3 forward hplas, and whatever else you can fit.
If you aren;t flying at least a raptor by now, you're in trouble.
Alexander