I am in US on an H1-B. My wife currently has an H4 visa valid until Aug 8th 2010.

She works for Price Waterhouse Coopers in Bangalore, India.

Her company is willing to sponsor her B1 visa so she can be in PWC's office in the US for a few months.

Question 1 - Can she show up at a consulate to apply for a B1 visa while she already holds a valid H4 visa?

Question 2 - What happens to her H4 visa if her B1 visa is rejected? Will the H4 visa become invalid?

Question 3 - Can she enter the US with her H4 visa first, and then have her company apply for a B1 visa while she is here in the United States?

Question 4 - Is it true that the US Consulates in India have reduced the B1 visa validity from 90 days to 45 days, due to abuse?