Agreed. It's a bit circular though - a formal accusation of wrongdoing brought by the House is by definition, impeachment.
-- And only upon impeachment and conviction may an Officer of the U.S. be removed --
That position is that the president cannot (constitutionally) fire Officers. Only the Congress has that power. I'm not saying Congress doesn't have that power - just that it is not the sole possessor of that power.
Otherwise the firing of Comey, for example, was an unconstitutional usurpation of Congressional power, by the president.
Nitpicky remark on my part, the correct word is "cited," rooted the same as "citation."
I believe Comey would come under the heading of “inferior officer” which doesn’t require Congressional impeachment and removal.
Yes, I tend to screw that up - “cite”.