I am Physical Therapist and a consulting company filed my H1B in 2010 (H4 to H1B) but I never got on payroll as employer wanted to wait for my SSN. Now I got my SSN but employer want me to work in “home health” area (which was not mentioned to me before filing H1B) and sign new employment agreement, which has more stringent terms, esp. for ‘breach of employment’ than were in offer letter. Employer is giving me option to not start work with them and leave without any penalty.

a) Is employer legally bound to employ me in above case? Can I take any legal action against employer for falsifying and wasting my one year?

b) If current H1B remain unused:
1)Would there be any risk if I file new H1B petition this year?
2)If I leave US (with H1B unused), can I re-enter on my valid H4 stamp?