How many valves are there on a 'modern' French horn?

How many times does the main theme ('tune') come round within this movement?

This piece is marked to be played . Which of the following does this mean ~ as though you probably couldn't have guessed?

There is a famous and much-loved song version of this piece, supposedly telling the story of someone who learnt the horn precisely so as to be able to play this (cheerful but tricky) movement ~ and then whose instrument was stolen. What were the names of the duo who wrote and popularised this version in the 1950s?

The rhythm of the piece is technically known as 'compound duple time' (i.e. two main beats, each subdivided into 3 rather than 2 or 4; 'gallopy-gallopy', etc.). In simple terms, how does this appear as a time-signature on the score and parts?

The horn generally sits well against, or near, the human body. What total length of tubing is contained within the instrument?

The horn is a notoriously difficult instrument to make sound steady and attractive (even more so than the dear violin; or than the keyboards, where at least the notes are 'already there' and one merely has to hit them in the right order). In common with other brass instruments and also the flute, it needs very special techniques in the actual blowing, quite apart from any fingering issues. What is the correct musical term for 'applying one's mouth and blowing'?

What is the technical term for what happens around 3 minutes into our recording ~ when the orchestra 'pulls up' and the horn plays entirely alone, in flexible time, for a while before everyone returns to the main tune?

This movement is scored for solo horn (obviously enough) plus two 'chorus' horns in the orchestra; what other wind instrument/s, if any (i.e. brass or woodwind) are required?

The whole sound and rhythm of this piece is powerfully evocative of which activity, that was probably done a great deal more in Mozart's day?