IF everything happened is to God's plan. Then there's no "miracle" and no "accident", since He planned them?

Yes and by extent ion there is no free will. Hence god knows who is going to heaven and who is going to he'll and it doesn't matter what you do. So if you believe in what some folks say about repenting, etc., if you do it's in the plan and if you don't it was the plan. So your final reward is predestined and you are playing a rigged game.