Construction of actual corsair, privateer or dedicated raiding ships requires a compliant governing authority.
Exactly, and that point cannot be made often enough. Political cover, either passive, active, or somewhere in between, is a
necessity. That political cover does need to come from Capital, Zhodane, Gram, or Lair. Cover can be given by any number of "lesser" governing authorities just as was done in history.
Beyond Drake's Golden Hind, think of the Alabama.
Another excellent example. James Bulloch, Teddy Roosevelt's maternal uncle, spent the Civil War in Europe arranging for the construction, arming, and supply of commerce raiders in both the UK and France. His activities involved skirted, bending, and flat out breaking local laws, bribing officials, and coming to
"Nudge, Nudge, Wink, Wink" understandings with government authorities as lofty as Napoleon III.
In most cases, the new raider was completed but not armed then left the yard to mount her guns in "international" waters. The
Alabama, for example, steamed from Liverpool to the Azores where it took aboard guns and ammunition shipped as cargo aboard another vessel. In the case of
Sphynx/Stonewall, that ironclad ram was completed in a French yard with guns purchased in the UK while the Second Empire pretended not to notice. When the weight of evidence provided by US diplomats could no longer be ignored, France blocked delivery to the shell company which had paid for it. That's when Bulloch's agent on the scene finagled a phony sale to Denmark with the help of of a few friendly Danish officials. The ram steamed to Denmark where the Danish government disavowed the actions of it's own officials and impounded the vessel. That's when the real crew boarded the ram and steamed away as had been planned all along.
A corsair, privateer, or pirate is going to need a compliant authority on some level in some place for some period of time.