Keep all your documents with PoF ready for your full doc submission to your local office. You will also need to submit CAD490 towards RPRF, so have enough funds ready.
You don't need to worry about AOR, it is just an acknowledgment that they have received your application and an file no for future correspondence and online status checking.
It will be v difficult to say, but according to this forum, most of the verification is done before medicals. But they can n might do it until you get the PR stamped in your passport. So there is no hard written rules regarding this.
I believe it will be v difficult to prove IT administrator is same as IT manager. They are looking for people who have really worked on IT Project management or in the management category along with some technical experience.
I myself have to add surname for my daughters and spouse. I thought of doing it after I get through the passport stamping stage. I don't want this to cause any delay in the process. Changing name is legal as far as you have all the proof of both the identity and follow the process, like court...