Ah yes. As for the destruction of that homeworld: using the Yvelon's own logic, (which they applied to the Terrans), that was a military target. Homeworlds have a high construction rate and can produce dangerous ships fast. We intend to destroy another one, then turn our attention to the main Yvelon fleet. After that, our objective will have been achieved and we can sue for peace, helping the Yvelon to build up the remains of their economy. (hoping that their defeat on the military level has dissuaded them from any future militaristic dreams).
What won't help their economy though is the planets they destroyed (abandonded) all on their own