If your wife sponsors you for PR, you can choose inland or outland sponsorship. If you are still living in the US and she sponsors you for outland, the part that takes about a month is approving her as a sponsor. That does not mean you get a work permit. That means that your file will be sent to the US and continues to be processed there for a few more months, see http://www.cic.gc.ca/english/information/times/international/05-fc-spouses.asp#west If you are lucky, you can have your PR in under 6 months and then you can work in Canada all you want, no work permit needed.
If you move to Canada first and then apply for inland, you could have first stage approval and work permit in 5-6 months but PR much later.
You could look into a NAFTA visa if your occupation is on their list, see http://www.canadavisa.com/nafta-temporary-work-permit-canada.html and it's supposed to be easy to get.
1. You are confusing the outland approval of sponsor with inland first stage, see http://www.cic.gc.ca/english/information/times/canada/process-in.asp#perm_res
2. If you apply inland, you would have to send a work permit application with your file.
3. You can not file for inland unless you are living in Canada.
However, inland is not really faster than outland and it does have drawbacks like you are not advised to leave Canada while it's in process and it can take you 1-2 years to get PR. If something goes wrong with this application, you also don't have appeal rights although you could then apply outland.