Surah 4: Contradictions

1. Can a man treat his wives fairly? 4:3, 4:129
2. Will Allah forgive anything? 4:48, 4:110, 4:116, 4:137, 4:168
3. Is Allah merciful? 4:56,4:168-9
4. Is each person free to believe (or disbelieve) whatever he or she wishes? 4:89, 101, 144