door to door pay

All depends on the individual contract, mine used to be pay from when i turn the key at home but they changed it so i have to drive to first job unpaid upto max 30 mins and gave me 5 days extra holiday instead which seems like a weird decision but im happy with an extra week off and most of my jobs are within 10 mins of home

From when you leave to when you return

My last company would have interpreted that as from the time you climb out of the van when arriving on site. Or any other method to short-change you

It doesn't mean anything, or rather it means what they want it to mean.