A redated post.
First off, I think you're right when you say that you're at a disadvantage when you, as a theist, must first set out your proofs for god and how they square everyone's observations of the natural world. It's not an unfair disadvantage, though; it's perfectly fair and right that things are tougher for you than for the atheist, because you're making the positive claim ("God Exists"). If you want that claim to have any weight, you must present the positive arguement and then let others attack the logical edifice to see if it holds together. What you're doing right now is just avoiding your responsibility at a theistic philosopher, trying to get the athiests to do your work for you. I can understand why you want your opponents to play the besieged party (it's easier to be on the attack, sure), but just because you don't want to do the work of establishing your premise doesn't mean you can assume it's true and rest on your laurels.
There are some mistakes in this discussion that need to be addressed. First of all, I am not at all sure that "making the positive claim" places a burden of proof on the theist. Until somebody converts me to classical foundationalism my view of burdens of proof is that the burden of proof falls on someone trying to get someone else to change his or her mind. We have the right, as rational persons, to believe what we already do believe, unless we receive evidence against what we believe. Someone claiming that the external world exists is making a positive claim, so by the above logic he or she should have to prove to a skeptic that the external world exists in order to be rational in believing it.
Second, I have myself defended theism with arguments. So that isn't my problem.
My problem is this. The argument from evil is the attempt to shoulder a burden of proof on behalf of atheism. It is, after all an argument for atheism. It as attempt to argue that God does not exist. It is an argument against theism. For it to be successful, we need to see how it works, what moral principles are invoked, and what factual claims are being made, to see if the argument is a good one.
What I am objecting to is what I will call atheism-of-the-gaps. Theists are rightly criticized when they take a gap in the naturalistic understanding of the world as automatically proving that God must exist, so that the gap can be filled. A gap in our scientific understanding of the world might be as a result of the limitations of our present understanding rather than providing a foundation for world-view change. But when they come to the evil in the world, they point to some evil and say "Explain this, otherwise, you're being irrataional." This in spite of the fact that the omnipotence of God and the teaching of Scripture strongly predict that there will be gaps in our understanding of evil.
Now we need something more than the contention that we have a gap here.