No, I do not believe this is a limited hangout.
The Russian FSB is far too sophisticated to be used by Snowden and CIA as a tool for a limited hangout operation, unless both the FSB and CIA had some weird conspiratorial deal, which I highly doubt.
It is my belief Putin would not have allowed Snowden in Russia if--I believe-- the most sophisticated FSB interrogators, interpreters of body language and other methods of reading individuals or FSB usage of drugs to "enhance the likelihood of truth being divulged by Snowden" likely debriefed Snowden.
Having myself worked within government, no highly trained clandestine operator can withstand the interrogatory of an extremely sophisticated group of intelligence officers interrogating the operator.
Truth is usually given up quite rapidly, usually within 48 hours if drugs are used to get the "truth out."
The only operative that would withstand such an interrogatory is a cutout, which is usually a sacrificial lamb who does not know why or how he had been used--or an operative that has been preprogrammed via hypnosis and NLP or drugs. This is unlikely due to the amount of resources and time needed for the creation of such operators, who are usually trained for direct operations.
The FSB is an elite organization that has countermeasures to test for these particular variables. Their methods are on par with CIA or may be better, it is impossible to know.
I believe Snowden was an FSB asset and recruited while he was in the U.S. intelligence apparatus. His FSB handler likely ordered his smuggling out of the country to China and sharing of information with Greenwald, who himself is an FSB cutout or knowing FSB asset as well--surprisingly living in a country without airtight extradition laws to the United States.
Putin has revamped the FSB and GRU, with a great focus on HUMINT, so it is not beyond reasonable to believe that the aforementioned is true.