My case: EB3(PD 03/2005), Masters deg, 140 approved, 485 pending. Valid EAD until Jan 2011, AP until Jan 2010. 2 years left on H-1B.

I'm looking to switch jobs to a small(<10 ppl) company in the bay area and would like to use my EAD as they're hesitant about the H-1B/LCA having never done it before. It also saves time on my H1. I can invoke AC21 portability and join them using the EAD.

1. Do they need to file the Labor & I-140 for me after I join?
2. The job is in a similar position(Sr. Software Engineer), however the underlying skills/languages are different than my current job. Is that OK?
3. What if they don't want to file Labor/140. Can I still continue working there on my EAD? And extend EAD/AP when required. I may move to a more willing company after a few months.
Thanks