TRAVELLING FROM TORONTO TO BEIJING ON AIR CANADA AND TRANSFERING TO AIR SINGAPORE TO SINGAPORE

WE HAVE A 5 HOUR LAYOVER...WILL OUR LUGGAGE BE CHECKED THROUGH TO SINGAPORE OR DO WE HAVE TO COLLECT? WHAT ARE THE VISA REQUIREMENTS FOR THIS TRIP? ON OUR RETURN, 28 DAYS LATER, WE ARE TRAVELLING ON AIR CHINA FROM HONG KONG TO BJ AND TRANSFERING TO AIR CANADA TO TORONTO WITH A 3 AND 1/2 HOUR LAYOVER.....WILL LUGGAGE BE CHECKED THROUGH AND WHAT ARE THE VISA REQUIREMENTS FOR THIS LEG OF THE JOURNEY?