H1b transfer case: chance of visa stamping rejection?


I got my H1b visa stamped in 2011. The stamp expiry date was Aug-2013. I never joined the company and did not enter US on this H1B visa. Now another company is willing to transfer my H1B. My questions are:

1. Once h1b transfer is approved and I go for visa stamping in US consulate in India, Is there any chance of rejection at that time also?

2. My passport is getting expired in Sep'2014. Will it create any problem during h1b transfer filling? Do I need to get it renewed first and then go for visa stamping or after stamping I can do this after completing the visa process? 

3. Let's say I enter US now then I would have next 3 years remaining to work there on this h1b visa (because my visa got approved in 2011). What after 3 years? What is the possiblity of h1b visa extension after 3 years? Would I be able for the green card?


- BK