Bringing my gf to Canada

Hi...
I don't really know where to post my questions, because it's somewhat broad.  So please bare with my dim witted mind.  I have read through pages and pages and pages of Canadian Immigration and Visa info, applications, requirements but none of which really answers my questions directly. They're all kind of condition-based, but there are no "What if" answers.  So your help is greatly appreciated.

Background
I was born in Canada.  I work and live here in British Columbia as part of an IT development company.  I have a girlfriend of roughly 1.5 years who is not a Canadian citizen and she lives in Germany.  She has no problem coming over for 6 months as a tourist.

Goal
The goal is for her to eventually get her citizenship here in Canada. If she can live with me through extended stays, I can sponsor her as a common-law spouse after about a year. I don't know if this is how the common-law label works in Canada mind you.  Also, she will primarily be dependent on me.

Job Situation
She is 23 years of age this year and already has a part-time job in Germany as a non-skilled worker. I already read about the Work Permit and LMO, but those require a letter from a potential employer in Canada.

She wants to be able to find a job in Canada as a non-skilled worker, eg: waitress, filing, general office manager, etc.  However, she wants to be able to do that when she is actually here as a visitor.

The Dilemma
Now according to the Canadian Immigration and Visa pages, she can't really work in Canada until she gets a permit, but she can only get an LMO from a potential employer.  I am pretty sure that she won't be able to find a potential employer here in Canada who is not a professional company to write a letter to the govt for the LMO.  So what can we do?

Personal Ideas that might not work
I was thinking to bring her here as a visitor and live with me for about six months, then apply to extend her stay when five months has passed. During those months while she lives here with me, she can apply for a Work Permit.  If she is allowed a Work Permit, then she can look for a job and the potential employer can write a letter for the LMO.  If all that works out, then she can finally work in Canada and through her Work Permit and extended stay, I can eventually sponsor her to become a Canadian citizen as my common-law wife.

I don't want to marry her right now and sponsor her as my wife, due to personal and family reasons, but marriage will come eventually. Just not now.

Questions
1) With all that said, is that possible? Is that how it can work?  

2) OR, does she NEED to apply for her Work Permit and/or LMO BEFORE she comes over to Canada even as an unskilled worker?

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Anyway, this has been stressing me out.  It's so difficult trying to get my gf to be with me with all these obstacles between us.  All we want is to be together, live together and build on a future together. She doesn't need to work here in Canada, but it would make both our lives a lot easier if she can, because then she can help with the expenses between the two of us.

Thanks for your help.

Thanks for the response Scylla. 

Can she apply for a Work Permit while inside Canada or will she need to go back to Germany to do that?