All immediate family is actually your spouse and dependent children. I am not sure parents are considered part of the immediate family for lounge access (I could be wrong and if I am then I will be happy to learn something new today). Best bet would be to ask for spare MLL passes from other members.

This is what AC has on its website regarding lounge access:
Air Canada Super Elite and Elite members, along with their spouse or domestic partner, dependant children, and one guest, are entitled to access the Air Canada Maple Leaf Lounge when departing on an Air Canada or Air Canada Jazz flight, or a flight with any Star Alliance carrier.

So your parents would be considered your guests.

As for op ups for your parents. If you are unwilling to part with your eupgrade credits for your parents then why should AC give them an op up?? I would plan on parting with the eupgrade credits if I wanted to upgrade someone.