2 quick Qs about changing my status from Work Visa to Visitor status...

Hey folks,

got no responses from The Working Visa forum so I thought maybe this would be a better place to post this:

I'll try to keep this very brief and succinct this time:

I am trying to change status from a working holiday visa to a tourist visa to stay in Canada and do some travelling when my work visa expires ( in 4 months today) - for maybe 2 or 3 more months with savings from my job. I am an Australian passport holder, and do not ordinarily need any visas to come to Canada as a regular tourist under normal circumstances.

Here are the 2 questions concerning me most:

#1 - If I apply for a change of status ( work visa to visitor visa) and it it approved ( and all indications from the C.I.C website suggest it would be, and fairly easily too) will that take effect from the day my working visa expires? Or would it take effect immediately, as soon as it was approved and came through? Ie. Would I end up losing a portion of the period of my work visa period ( which I cannot afford to do), if I apply to early? Or would it simply take effect from the day my WV expires? DOES ANYONE HAVE A DEFINITIVE ANSWER TO THIS?

AND

#2 I am scheduled to spend a week in the USA with a friend mid-May (When my current work visa would have expired)
Would I be able to travel to the USA and then re-enter Canada under my implied status? Or would I need to wait for my Visitor visa status to take effect before I can leave and re-enter Canada? [ I will have details of a booked flight out of Canada to Australia booked for a few months later to show to both US and Canadian I.O's in any event by the I take this trip in May]

Basically what I want to know is whether I will have any problems - Canadian I.O-wise - in travelling to the USA and re-entering Canada, being on a VISITOR VISA at this time, as opposed to the previous lack of issues I have experienced under my WHV??
And would Leaving to the US and re-entering Canada even be possible whilst I am under IMPLIED STATUS???

And feedback or definitive answers would be greatly greatly appreciated...

cheers,

GoRaptors