Can the talent be activated like so:

spend maneuver to move

spend action to scathing tirade

activate quick movement (suffer 2 strain) add FR to check.

roll check, results in 4 light side pips, spend all 4 to move two more times.

Basically, if you exceed the basic 2 force points, can you spend additional points or are they wasted?

Only the 2 force points to activate it once. No additional movements for more force points.