E3D visa: impact of a new I-94 on EAD application-in-progress if I go overseas for a holiday and is Advance Parole required?

Entered US last month on E3D visa valid til 2014. Mailed in EAD app last week, including copies of my current I94, now planning overseas travel in Oct while the EAD is being processed (Principal E3 holder remaining in US) Q's: 1) Will my current I94 have to be surrendered when I leave US or can I keep it, as it's part of my EAD submission? 2) Will leaving US/receiving a new I94 number when I return to US impact my EAD app in any way? 3) Is the Advance Parol permit relevant here as I have a pending application? 4) With a valid E3D visa, is it correct there should be no issues with re-entry to US? 5) Can my partner respond to USCIS on my behalf while I'm away i.e. move any biometrics appointments? Other advice to be considered also appreciated, thank you.