"Karmic trajectories rush inevitably to balance forces when no further actions continue manifesting results which themselves must be appropriately paid."
"Karmic trajectories" = the general trend, apparent path of the ship of any "self". Some people seem to tend toward the good and others toward the worst (of choices). Trajectory is not fate but more like the momentum of a large ship at sea. It can slowly be changed.
"rush inevitably to balance forces" = the momentum of cause-effect (action-result) seeking equilibrium = arc of the moral universe (a near universal value).
"when no further actions continue manifesting results" = (awkward sentence construction) until we cease adding more momentum to our trajectory, we continue accruing karmic debt (imbalance). Our continuing actions bring added consequences that need resolution, while we carry still outstanding previously accrued balances.
"which themselves must be appropriately paid" = in the 'karmic-model' and in common-mores, we postulate that the consequences of our actions will be adjusted (debits and credits balanced); some say death is less final on a moral scale than on a human scale.
Karma-ethic ought to be thought of, less as reward-retribution-punishment, and more like gravity- unseen but certain.