Another work permit(wp) question

Hello, I am from the States and have been considering on moving up to Canada. If I am able to move up there, I would living with a friend I have. So here are my questions:

- Is there any way at all to be able to apply for a work permit from -inside- of Canada? I've read on the CIC site that I can apply for a WP at the border. My friend said she might be able to get me a job with her at a grocery store-type deal that she currently works at.
- Would arriving at the airport/going through customs and all that be considered the border? Or is it physically crossing the border on land?

- If I do need to apply for a WP from the States, what is the general wait time to recieve a response? I know I saw a link to a previous post, but it lead to a dead link. My planned date to move would be sometime late-May to early-June. As I have financial obligations to take care of now.

- Would having certifications add points for eligiblity to apply as a skilled worker? (i.e - an A+ certification, NTSE, etc.) Though that is not my current profession, I plan on working an IT sometime in the near future.

- If I do work in Canada and my WP is near expiration, would I need to come back to the States to re-apply for a new one, or would I be able to do it from within the borders of Canada?

Here is some personal information about me. I am 21, I do work at a clerical job right now(but I don't have the points to qualify as a skilled worker), and the province I plan on moving to is B.C.

~Thanks to those who reply
GKP