How long can I wait on EAD card to find a job in same field

[nike.yo]

Hello 
Working on H1B visa and my current company transferred my H1B visa and filed successfully filed AC21 to port my Green card EAD card.I have EAD/AP card and I-485 pending for 5 yrs in EB2 Category. 
My question are - 
1)If I lose my current job so will lose my H1B status immediately.But Can I get another job in same field on my EAD card? 
My EAD card is valid for next 2 yrs 
2)Approx How much time I can wait to find job on EAD card?I mean can I find job in 4-6 months staying on EAD card?

[pontevecchio]

See your other post.