Those are really good points about suffering. And, obviously a question that all faith based worldviews must wrestle with. I don't have a perfect answer but my Christian perspective is something like this:
God's will was to give us meaningful free will - our choices have consequences, and we even have the right to go against God's will e.g. we can hurt others
Our fate/destiny isn't concluded in mortal life but eternal life. Judgement Day which is often displayed as a bad thing in media portrayals of Christianity, is also a day when every wronged person receives the justice they were denied on earth. Every innocent victim will be validated and restored.
Eternal life is longer and happier than this life, to such an extent that even the most awful sufferings we face in this life will fade away in perspective of eternal joy.
To an extent all people experience part of God's goodwill towards them: through the beauty of creation , and our ongoing existence.
But those who choose to trust in God and dedicate themselves to Him experience a greater involvement of the creator in their lives than those who don't. They are more protected from evil, receive more blessings and are promised eternal life and justification. However, the Christian may still undergo suffering and mistreatment in this world (in fact the Bible promises that they will) but because they are completely in God's care, they know even what is used against them will also be used for good (by developing character or by demonstrating their commitment to God/righteousness)
Christians believe that you can enter into this pact because of Jesus. And we follow his example and attitude towards destiny. We try and do good, as our life's purpose, we are grateful for the good, and we accept the bad, believing in a greater life to come after death.
Sorry, that's a long and still incomplete answer. It's a big topic!