What's an effective way to play Chizuru?

So when using the +2 hit epiphany playstyle, how often should I play her bind card to maximize damage? Should I wait until bind 5, or should I play already at bind 3?

When I am trying to wait till bind 5, it feels like my dmg is just to low until then and I get hit a lot. And since Tressa and Rei can't heal as well as Mika I often reach low health.