I can give you a bit of information!
1)My husband had the same situation with medicals, we did his again prior to being asked and I think it speeded up the whole process. His expired in May 2011, we did it the end of April and he got his PPR on June 17. I'm sure if we hadn't done it that it would have added another couple of months to the process.
2)As long as you've submitted your visitor visa extension application you can remain here until you get a decision from them (regarding the visitor visa) with implied status.
3)No idea
4)When they ask for your passport, you send it to the Vienna office, they put the visa in and send it back to you (here in Canada). Then you have to leave the country and come back across the border to "land". You can just drive to one of the border crossings (but check to make sure the one you go to does immigration stuff!) cross over to the US and then immediately come back into Canada to land. You don't have to travel to Vienna to get the actual visa. My husband's passport is currently in Paris, we're just awaiting its return and then we'll drive down to the border to "land".
It is very frustrating, some offices seem to take much longer than others - we were lucky, my husband got his PPR in 4 months 28 days, so we were fortunate. Hang in there!! At least you're here with your wife
