Travel Before EAD arrives

[montyi]

I have filed 485 and Myself on H1B with valid 797 till 2016 and not being visa stamp. My wife is on H1b on 6th. Her current 797 is till Oct 28, 2014. Her company is filing new 797 till Dec 8 2014 for the vacation time left outside US. 

485 filing status 
- USCIS receipt date Sept 6 
- Fingerprint Oct 2

What are the options for my wife if EAD arrives after her 797 expiration Dec 8 2014 ? 
1) She can stay without any change in status as 485 have been applied. 
2) She need to change to H4. 
3) She need to travel outside US 

What are the options and documents process to be done if we plan to travel outside US before EAD arrives? 
1) We both travel outside US before EAD arrives. 
2) Myself travel outside US before EAD arrives and mywife stays in US till EAD arrives and then travel outside US. 

Thanks