Firstly, a great site!

I will be travelling new direct service (goodbye LAX:-) AC34 SYD-YVR 22nd Dec and connecting to AC130 YVR-YYZ approx 2 hours later.
I have looked up YVR official site and AC site but still confused!

1. Can I check my bags through to YYZ from SYD?
2.Do I clear customs/immigration at Vancouver and then board domestic flight to Toronto (AC130), or stay in same terminal and undertake clearance in YYZ?

I'm confused by terminal maps etc, not sure if it is because I am new or it is a late night!

Thanks in advance for your help!