If so, then please cite the provision in the U.S. Constitution where it says this confirmation is required.
If not, then what exactly is the basis of your constitutional objection to the appointment of a special counsel?
You're the one with the bigger problem here. You have taken an appointment of a Justice Department official and extended this appointment to an assumption on your part that Mueller's appointment is the equivalent of the impeachment of the President of the United States. Your logic doesn't follow, and they don't reflect the facts on the ground.
Like I said before ... your input on this thread would be applicable if Mueller actually indicted Trump, but until then it is all just wild speculation on your part about what may or may not happen in the future.
1) Depends on whether he is an "Officer" of the U.S. or an "inferior Officer". His role and power might suggests the former. If so, the appointment is under Art II, Sec 2 Cl. 2.
2) Let's assume without agreeing he is an inferior officer. The issue is his ROLE as "special prosecutor" which is to go after the President's campaign which is to go after the President. As I've previously sited, the Constitution gives Congress SOLE power to impeach (which includes going after, investigating, and charging) and try ANY officer including the President (U.S. Const., art. I, sec. 2, cl. 5; art. I, sec. 3, cl. 6
If you cannot site constitutional text accompanied with reasonable explanation that justifies this federal action that is a prima facia violation of these clauses, we're done.