Yes You can land and come back in a week or two weeks time. i am doing the same. If you give them a mailing address (your relative or frd in canada) then they will post your PR card on that address and then they can send it to you in PK. If for some reason God forbid PR card does not arrive you will have to get a travel document from Canadian embassy in Pakistan for each family member by paying a 50$ fee.
2. They wont mind as long as your wife can travel within the visa validity period. But many airlines do not allow pregnant ladies to travel when they are in their last trimester.
3. That would mean that they have to start from scratch, you should have informed the VO about uexpected kid at PPR1 stage. in my humble opinion if for some reason your wife can not travel before delivery then you should land after delivery without new born and come back to Pakistan after landing and then when you have returned to Pakistan you should inform the embassay that you have a newborn kid, so you should not get a birth certificate now, you should get one when you have returned back with those dates.
4. It is msut for everyone to make an entry before the visa expiry date.
5. you can enter at any POE, but if you land in Qubic then it could be a little problematic.
6. You can take proof of funds in any form. Most of the time they won't even ask you to show POF. They only ask you if you are carrying in excess of 10 thousand dollars. I had only 3600 CAD when I landed, he asked me how much money both of you have, we told 1800 each. He didn't even ask about rest of the POF. We had bank statements, which would have been fine even if he had checked.
Hope it answers everything. Best of luck