missing home and retouching

[David Emerling]

Situation: R2, two outs. Batter gets hit into outfield scoring R2. BR is thrown out at 2nd for the third out trying to stretch his hit into a double. R2 crossed home before R2 was thrown out -BUT- R2 missed the plate, takes a few steps toward the dugout, is informed by a teammate that he missed the plate (which he did), and he retouches. But the retouch occurs *after* BR is tagged out at 2nd.

Here are my questions:

Isn't it true that when R2 "passed" home he was considered to have scored at that time, even if he had missed it? Because, isn't it true that an umpire is not supposed to "recognize" a missed base unless there is an appeal?

When the third out was recorded at 2nd base - wasn't the inning officially concluded? Can live action still continue? Can R2's retouch count? Can't the defense appeal that he missed home even though he came back a retouched?

What's the ruling on plays like this?

As always, I'm interested in both the FED and OBR interpretation on such plays, if different.