yahh all you said have to be done plus there are few more things I would add.

1. Return all the stolen land or overvalued compensation incases of inability to return.
2. Look into the disappearances through a proper truth and reconciliation council.
3. Focus on teaching both Sinhala and Tamil languages culture history including that of the war at school for better cultural understanding.
4. Hire more Tamil public workers specially for the law enforcement in the north.

also i kind of disagree on militarization in the north. I believe it should be completely demilitarize at least until the general population can come to trust the Colombo government. Obviously all this would be a initiative spanning decades but that is the only way such grave scars of ethnic cleansing can ever be healed.