You don't need to courier anything, just print it out and sign it.
And no issue dating it earlier than it was actually signed if that was what you meant.
Interesting. But most likely the application will be refused as you don't have a valid passport.
You can apply without an explanation and try to make an update afterwards when you get a new passport.
You mean a visitor status? Why would you need to covert?
If it's primary or secondary, they won't need a study permit if you have a worker status. But they need a status anyways so the kids can apply to change for a visitor status .
It might help
How can I show a potential employer I’m allowed to work while I wait for my post-graduation work permit?
You can show a potential employer you’re allowed to work by giving them a copy of all of the following documents:
proof that you completed your program(s) of study, such as...