My reasoning from theism to atheism was related to yours, but somewhat different. I also thought about the improper fear-basis of belief, but I found many many other reasons to reject my former theism (you probably did too). I'll mention three more that come to mind right now.
1. I concluded that since Mormons and non Mormons were blessed essentially equally and everyone had free agency to do whatever they wanted while on Earth that it didn't matter whether you believed in God or not. Here's an analogy. Assume your father tells you that he'll let you live whatever kind of life you want without special help or hindrance. Once you retire at 65, however, he will give you a million-dollar mansion and a million-dollar-a-year allowance if you obey his list of orders through out your life, but you'll get nothing when you turn 65 if you seriously disobey. Is that any way to raise a family? No discipline or interaction at all until they're 65? That's essentially what my former religion implied. We have free agency. They claimed that God punishes and blesses us while on Earth and communicates with us, but the evidence contradicts that claim. Believers and non-believers on Earth are not treated any differently by God, otherwise you'd see insurance rates based more closely on your religious worthiness. To me, it was more reasonable to deny the existence of God.
2. I concluded that atheists would probably be as well off as theists in an afterlife. If you didn't believe in Him because of the atheist arguments then God would understand and forgive you since He made the universe look like He didn't exist. If you believed in Him because you were gullible and unscientific then God would understand and forgive you. Believers would only be moderately better off in the afterlife if at all. To me, it was more reasonable to deny the existence of God.
3. I concluded that the people I loved were more God-like than God appeared to be. If I or a loved-one would be a better God than the one people claimed existed then what good is He? Not very good, I concluded. To me, it was more reasonable to deny the existence of God.
And more reasons.