Re:1)we would say
scendere dal letto col piede sinistro
to go down from the bed (starting) with the left foot (pretending that it is wrong, bringing bad luck... apologizing to all the left people)


In the Maid-en Voyage thread, "footmen" came up-- and i know that footmen were originally servants (in ancient Rome) who assisted/monitored people entering a house, since it was considered bad luck to cross a threshold with your left foot..(almost no one has footmen any more)

We still use the express, Best foot forward or Starting out on the right foot when we want to say we are starting something, and want to show our selves off to the best advantage.

someone who is clumsy, or not very good at dancing will be described as "having 2 left feet"

i think this idea of left feet being unlucky is very old!