Regarding Canada PR..go ahead and apply for it right now. In this type of situation, you always have to pursue multiple things simultaneously.

And absolutely NOT necessary to hire any lawyer. I have many friends who have applied and got Canadian PR and nobody ever had to do anything with any lawyer. It's straight forward.

Some info on STEM - for people whose degree does not match directly on the list.

http://www.murthy.com/news/n_stemli.html

MurthyDotCom
My Degree is not on the List
©MurthyDotCom
If a particular degree does not appear on the STEM list, then it is possible to request the additional designation of a particular degree category. A link is available on the ICE WebSite for this purpose. In making the request, it is necessary to specify the CIP code and provide justification for expanding the list. Clearly, it is necessary to show the connection to the STEM category in order for the request to be considered. One should not rely on any anticipated change in the list.
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Conclusion
©MurthyDotCom
Many who hold degrees that fit squarely within the STEM categories will benefit from the F-1 OPT extension provisions. Others, with degrees that may have STEM elements, need to either ensure that their degrees are on the list or request classification, if appropriate. It is important to make NO assumptions as to one's eligibility.