Regarding hacking: Obama told Putin to "cut it out"in September 2016
https://www.politico.com/story/2016/12/obama-putin-232754
What I was concerned about in particular was making sure [the DNC hack] wasn't compounded by potential hacking that could hamper vote counting, affect the actual election process itself, the president said at his end-of-year press conference. So in early September when I saw president Putin in China, I felt that the most effective way to ensure that that didn't happen was to talk to him directly and tell him to cut it out and there were going to be serious consequences if he didn't. And in fact we did not see further tampering of the election process.
Multiple media outlets have reported that U.S. intelligence officials have concluded that Putin was directly involved in his governments efforts to meddle in last months election.
Obama on Friday would not directly confirm Putins involvement in the cyberattacks but implied that such an action could only have happened with the Russian strong mans say-so. It was the closest the president has come to fingering Putin directly for the attacks.