Are the Empire ships at an inherent disadvantage due to lack of shields?
Solution 1:
I've looked this up before, and found out this. To balance out the shield dilemma, Ties have a special ability called power conversion. You can instantly give a burst of power to engines or weapons. giving it to weapons instantly fills the energy guage, allowing you to give sustained fire. This slows you down, and decreases your mobility. Giving it to engines fills up your boost instantly allowing you to speed away. Republic ships can divert power too, but power conversion gives you an instant maximum burst.
Hope this helps. :)