There are two problems in your post I'd like to address. Two concepts that cannot be factual or rather, true when confronted with the reality of Christ's atonement. First, and foremost, the idea that God decides to have mercy on someone, outside of Christ, so that they may be saved. This idea is an attempt to pretend that God in His sound mercy and judgement decides, "You know what? It was understandable given the situation so I'll save them." What does God's word say? None come to the Father except by whom? Jesus Christ.
The Gospel is plain, it is simple. Jesus is the savior. God doesn't save men outside of Christ, He saves them through faith. He doesn't save people at His whim, or in His present mercy (as if one day He is like "nope", but on another day He is like "sure.") He doesn't look at the alcoholic and say, "You know what? He had a rough childhood and now he is drinking away his sorrows. I'll excuse it." No, He looks at the sinner and says, "I love you. See what my Son has done on your behalf? I am yours and you are mine, if you believe in My Son who died on the cross for your sins and was raised on the third day for your justification you shall be saved." There is no whim or mercy that God extends in the realm of salvation outside of Christ.
As for suicide leading to Hell, here is a simple proposition. Is suicide a sin? If your answer is yes, then I ask you, did Christ's sacrifice pay for all sin? Did Jesus not pay for the sins of the world? Did Christ not shed His blood for the remission of sin (all of it)? So then what sin of this world can condemn a believer in Jesus Christ who has made our sins of scarlet as white as snow? If suicide leads believers to Hell, did Christ really pay the penalty for all sin?