In which scenario do the different court systems in the U$.$S$.$ interact properly?

An Arizona resident drove through New Mexico to visit his college roommate and is hit by a delivery truck. When the New Mexico state court hears the case, the judge only takes Arizona law into consideration, since that's where the plaintiff resides.

When an employee tries to file a discrimination complaint against her employer in Maine after she loses in a Vermont state court, the Maine state court agrees to hear the case.

When an employee in Colorado sues her employer for sexual harassment, the state court judge applies federal law relating to workplace harassment because it extends protections to employees beyond those provided by state law.

A federal judge refuses to hear a negligence case that includes a state$-$based claim in addition to a federal one. She cites the fact that federal courts can never have jurisdiction over cases that involve state laws.