"To counter that God is pure evil, one need only show one single act of love on his behalf. "
No, TEC, this is a logical error. We colud make the same about Satan..one good act proves that he is not pure evil. Remember there is a saying in the new testament stating that "Satan is making himself appear as an angel of light" (this is a free translation from my language, english bibley may not have this wording).
Besides, we cannot judge wether an action of God/ Satan is made of love or not, we can only observe if the consequenses of that act are good or bad.
Then we have drastic examples, I don't now if you are a literalist, but literalist states that is was a good act making children drown in Noahs flood. Likewise that state that is was good coomanding the Israelitet to kill a lot of people that lived in the "promised land"!