Two separate processes going concurrently:

Family petition: My mother(US citizen) applied for me (unmarried son over 21). Priority Date is 10/08/2002. Have approved I-130 since 2007. Visa bulletin will be be current probably beginning of this month.
Employment petition: Current H1-b expiring 05/17/2009. Employer has not yet filed for extension. Have approved I-140 and received EAD last week.
Three questions:

1) Is it ok for me to submit I-485 through family petition and through employment petition both?

2) Is there a "conflict of interest" in adjusting status through two separate petitions? Which is more viable in this case?

3) Can I use EAD alone to work for current employer if H1-b expires and I-485 isn't submitted through employment?
Thank you