Forget EAD if your 140 denied.

It is very risky for you to use EAD, since you will loose your non-immigrant status once the 140 (and 485 natually) get denied. If you don't use EAD, even your 140 get denied, your current status (H4 or F2 or so) is still valid till the original expiration date. Play safe. Since your RFE is coming you will know the result in a few months anyway.