I am Indian Citizen. Entered US on H4 Visa Stamping (stamping from India). I Changed my visa status to H1 while in US. No H1B stamping in my Passport. My H1B/i94 expired on Nov 5th 2011 and Applied for H1B extension on Oct 6th 2011 on normal processing. I am still waiting for a decision on my H1B extension case.
My Spouse is still on valid H1B with an expiration date of Sep 2012. Here are my questions,

1. How long can I continue to work on by H1B extension receipt ?

2. If my H1B extension gets denied, can I go to Canada/Mexico for H4 stamping after my H1B denial ? Or do I need to go to India for H4 stamping.

3. Can I got to Canada/Mexico for H4 Stamping, before USCIS takes a decision on my H1B extension ? Or do I need to go to India for H4 stamping even for this case ?

-VV