I never see anyone use Y wings. What do you use them for in your attacks? I rarely see anyone using Han at this level. Most go with Luke or Kessen. I also tend to see a couple more meds on the heavies.
What I really see you missing, though, is a way to bait and wipe out the SC, which is probably what's getting you pasted. Imp defence relies almost entirely on the SC (unless they have L10 sonics around). Now, you can bait it, or snipe it, whatever works best for you, but sniping takes more build time for the air (unless you have Kessen). Most people use a bantha rider to bait it and a couple twileks to wipe out the bikes, or some hwks/fangs if it is something else. Or, keep them busy with Luke's spinning saber and let the heavies wipe them (required a bit better timing).
In your case, I'd probably swap the hero, swap a couple heavies for meds, and replace the jumps with baiting troops plus a few soldiers to round out taking down the outside elements of the base (which I'm guessing is what you use the jumps for now).