1. Weak: August and Citizen built a fort under the loft, and they played there for hours.
Better: After August and Citizen built a fort under the loft, they played there for hours.
Also better: August and Citizen built a fort under the loft; then, they played there for hours.
Explanation: And makes the two clauses seem equal. The other connections show a more specific relationship between the two clauses.
2. Weak: Melony destroyed the cabin and got mad at Homer for leaving the orphanage.
Better: Even though Melony has the physical strength to destroy the cabin, she falls apart emotionally when Homer leaves the orphanage.
Explanation: Better writing shows more connections than merely making two ideas equal, as and does.
3. Weak: Strayed had made a shambles of her life and she changed her name and started hiking.
Better: Strayed had made a shambles of her life, so she first changed her name then started hiking.
Explanation: Showing the temporal relationship provides better information to the reader than and can.