I-140 approval pending - H1 7th year

[reachme_atthisid]

Hi, I would really appreciate if i can get verified information on the following questions

My Priority date is July 2009. I am in my 7th year H1 extension and Visa will expire in April 2012.

My labor is clear, I-140 RFE was responded to.

1) Once I get my I-140 approved, can I switch jobs.

2) Do i have to start labor and I-140 in the new job again.

3) After April 2012, can I apply for Visa extension for my H1 with the new employer.

Please add if i have missed out anything.

Urgent response need. Thank you in advance.