L1B to H1 transfer (have old inactive H1)

[muke78]

Hi,

I am on L1B in US since October 2010. My company is transferring me from L1B to H1 this month (May 2012). Previously I was in US on H1B for 1 year during 2006-2007... my old H1 was valid from 2004 until 2007.

Overall I spen 1 year on old H1 in 2006-07 and 1.5 year now on L1B from Oct 2010 till now.

My questions are -

1. once my H1B is approved, can I work immediately or have to wait until Oct 1.

2. Do I need to face cap again as it is almost 8 years since I got my old H1 petition.

3. How many years would be left before I have to leave US.

Thanks a lot in advance.