As you noted, Angel One was hardly a primitive planet other than it's lack of warp drive. So perhaps in applying a civilian version of the Prime Directive, the sociological and technological level of the native population comes into play. There are "degrees" of the Prime Directive, and not simply all or nothing. The crew of the freighter, given their shipwreak/castaway status, may have been allowed to interact with the natives for their own survival. But not have the local Homo Erectus build temples to them, they would be require to represent themselves perhaps just as strangers.it also appears to be the only episode to explicitly claim that civilians don't have to obey the PD
But if they landed/crashed on a planet with our current level, hiding who and what they were might not be required under the civilian PD.
A culture with 24th century equivalent technology, but still lacking a warp drive could be openly contacted and traded with.
The safest debating, but obviously not the best or most accurate. Picard learned things about the Baku in only a few minute sitting across from Anij in conversation, that a duck-blind never would have learned. By sitting in a duck-blind you are isolated from the people you wish to learn about, you're prevented from immersing yourself in their culture, history and day to day life.Duck-blind missions are the safest way to gain information about a pre-warp civilization. Direct interaction is far more dangerous so the only other option is to study them from orbit or not at all.
Kirk more often than not, just walked up to people on various planets, introduced himself, and started talking to them ... the ideal method.
Much of the trouble with The Communicator was the result off the natives realizing that they were being surreptitiously spied upon. They rightly resented this.Who Watches The Watchers or The Communicator it ended in a serious mess
