when is it an appeal?

[CecilOne]

I know we have covered this before, but too many appeal topics to find what I wanted.

2 runners on, ball hit to deep outfield, both runners score. Throw is to shortstop, then pitcher in circle. No dead ball or time out.
All get set for next batter, but from dugout "throw to Hannah" (F5). Pitcher does so, no one says anything. PU steps out, watching.
Ball back to pitcher and play continues.

Please rule or comment:
1) if one of the runners missed 3rd, is that an appeal and an out?
2) if neither missed 3rd, is that an appeal and should the umpires say so?
3) R1 is PU resp., R2 is BU resp. because of R1 coming home