That is a few valid points. However, just because the Confederation has citizens doesn't mean that most of them are going to enlist. While the Kilrathi have their warrior caste and a society that emphasizes on honor and combat, they also have their lowborns and their utaks. Just like the Confederation, they had great military men and citizens who aren't in the military who was 100% behind the war effort, but they also had fools like Mandarins, anti-war protestors (like Dr. Torg from fleet action), Kilrathi sympathizers, and other forms of idiots (Forstchen gave his novels a very Republican feel, to give a political situation of the Confederation).
And even though the Battle of Earth did screw the military over, Confed had one chance to keep the war from going bad. This was said in the False Colors novel, in which Tolwyn said that right after the Battle of Earth, the Terrans should have followed up with a "strike that knocked the Kilrathi back to the stone age". This blow, given while the Kilrathi Imperial Throne was in total disarray would help keep the stalemate, if not turn the tide just a little bit. With the new carriers brought online and new equipment, this would have helped. But as Tolwyn said, the political leaders screwed it up by wasting away their resources on useless targets until the Kilrathi had a chance to "rebuild everything they had lost, and more".
And the Terrans did have other shipyards. The Trojan IV shipyards was untouched during the BoT (it was on the other side of the solar system in Jupiter), and they had "valuable" shipyards in the Tamayo system. But I don't think that, taking the 2669 situation in account, that they even rivaled the Kilrathi's. In all due effect, all the new Confed capital ships, carriers, and fighters didn't turn the tide of war in their favor - they just merely postponed the inevitable by about a year.