An elementary question - please explain a road rally to me

I'm aware that the Monte Carlo Rallye was 5 days - but:

i) is it on normal roads? If so, does the course change from year to year? Do they keep all other cars off the course for the 24 hours?

ii) Why in this movie does it seem to matter where the drivers leave from - i.e., where their homes are - to get to Monte Carlo? I was puzzled - who cares where they live!

iii) are there two drivers in each car who alternate driving to bear the strain of driving for 5 days?

iv) there's a reference in this movie to how few cars are left - why? Aren't there pit stops all along the way to cater to the cars and any small mechanical problems?

v) are there different classes of cars and thus different races? Along different courses over the same time period?

Thanks. They just assume one knows all about a road rally race.