Is This Possible?

Dominic Flandry, one of many Intelligence agents sent to investigate the crisis in Sector Alpha Crucis, captains a spaceship that is shot down and crash lands on the planet Dido. Despite this contretemps, Flandry manages to:

lead his surviving crew and their single prisoner on a long trek through an inhospitable environment with native help;

learn to communicate with a Didonian;

hijack a rebel spaceship, thus acquiring the enemy's secret code;

fly the ship to the sector capital, thus ensuring that loyalist forces, possessing the enemy's code, will be able to win any space battle and to destroy the rebel fleet;

murder the Sector Governor, whose injustices had provoked the rebellion;

return his prisoner to her husband, the rebel leader, warning the latter to flee and stay away;

conceal all this malpractice, including murder and treason, from his superiors, some of whom realize that they need men as capable and successful as Flandry.

But can one man really do all this? (If enemy codes are that easy to steal, then I am surprised that it has not been done before.)

On Talwin, Flandry, surviving with limited supplies in another hostile environment, had managed to:

persuade the native Ruadrath to radio the Merseian explorers, alleging that they were puzzled because they had found a frozen alien non-Merseian corpse;

hijack the airbus in which the chief Merseian scientist, Ydwyr, travels to parley with the Ruadrath;

fake a call from Ydwyr to base saying that Flandry was barely alive and that his captured ship should be flown to the Ruadrath so that Terrestrial medical supplies could be accessed;

recapture his ship;

escape from Talwin, taking Ydwyr as hostage;

evade Merseian pursuit by flying through a Talwinian storm, then orbiting around a neutron star;

conspire with Ydwyr to smooth over everything, including his own misdemeanors that had led to his capture by the Merseians.