For your first paragraph:
You may not know why God does what he does, but surely you can question whether or not it is right that he does what he does.
I'm trying to get you meditating on why these horrible things are permitted by God. The scriptures say God is all good, all powerful, and all knowing right? So why then does evil exist? You might say that Adam and Eve's sin is the reason the earth is fallen and we all feel suffering, but even if Adam and Eve's sin was true sin against God, why are we punished for what they did? If you have an answer I would love to hear it! But when I used to be a christian I never understood the idea of their sin somehow cursing us. The only explanations I could accept was that either God was unfairly punishing us, or that God does not exist, and that this is a tale told by the ancients.
I'm sorry about your grandmother. I share your pain. My grandfather died of Leukemia, and my twin brother developed a brain tumor forcing the doctors to remove his left eye. He is alive and well, but now he lives with one eye and issues from the medication. At the time I thanked God every day. But now I realize that no good God would give a helpless and sinless 11 year old a brain tumor, cause him to lose his eye, stunt his growth, and cause daily pain for him while he was on his medication as he was allergic to his chemo. What right does God have to allow such horrid things to happen to someone who at the time was so defenseless and had no clue why these things were happening to him?
On the book of Job:
This book shows that even if you do everything right, God will still punish you. The answer to Job's suffering is that we couldn't possibly know God's doings and plan, but either way, God is still breaking his own laws! He still punishes Job for no reason! The book says Job is completely sinless!... How do you rationalize that?