> There is also the issue that it seems safe to assume that many people at the CIA etc consider him a traitor and would like to assassinate him, given the opportunity, even if he could be assured of immunity from prosecution.

The US is known for supporting or conducting extrajudicial executions, but they all served a very specific geostrategic and geopolitic goal.

There isn't a single case of a political assassination case conducted out of spite, such as the one in the conspiracy theory you fabricated. There is also no goal to achieve, or win to be had, or position to be improved by assassinating Snowden. Snowden's relevance ended a long time ago. In fact, any of those conspiracy theories would represent an unequivocal loss for the US.

If anything, the CIA would be involved in protecting Snowden in the US from the likes of Russia to avoid a false flag assassination to embarrass the US.