Yes! He probably also typed the notes on a government-issued laptop, while sitting in a car which likely belonged to the government. His notes are federal property that did not belong to him.
If his laptop belonged to the Feds, and he returned it when he was fired, how is that he still has a copy of the notes? He must either have printed them out, or, more likely emailed or transferred them to his own computer at home. Then he emailed them to his Columbia friend and asked him to give the memo to the NYT. Besides the notes being the property of the US Government, if he didn’t consider his notes to be “classified”, he certainly must have considered them to be “sensitive”. It sure seems to me that every action he took in this chain of events was illegal.
But, just as you said, nothing will be done.
Comey's conclusory assertion that the contents of his memo are not classified should be challenged or tested.
The NYT article contains several pieces of information. Flynn is under criminal innvestigation by the FBI, the president may be involved in directing the course of this investigation, and the FBI director is at odds with the president of the US.
Could this information be used to the detriment of the US government?
-- But, just as you said, nothing will be done. --
On this subject, it's all in the political realm. I agree, no legal ramifications of any significance. Maybe some temporary legal discomfort. But the political and credibility fallout potentially has epic proportions