On the Saturday question, some companies work alternate or all Saturday mornings. This is more common in local companies than in multi-nationals. Clearly if Saturday is a working day then you will need to take leave not to work.
Leave allowances vary considerably, but the most common seems to be entry level of 12-15 working days per year, with a scale rising with years of service to 20 days per year. More than 20 days is quite unusual.