He was certified as President, so he can be impeached.
Not with this congress.
This is nonsense. The executive power of the people of the United States is vested in him. Impeachment and removal from office would take this away and vest it in someone else. He can stay in the actual office if he likes, but the authority to act in the people’s stead would be gone.
The votes for him were certified, I don't recall hearing, seeing, or reading that he was certified. It's not the same thing you know.
Unless you count Nancy Pelosi's certification to various state Secretaries of State that he was qualified under the Constitution. (She did this as head of the Democratic National Convention, after his formal nomination). Not all states require that, some only require certification that he is the candidate of the party.