Miss Terry Solved
Here is how it is (I think, yea I'm not a lawyer).
You file AP, EAD, 485. All 3 are independent of each other to a certain stage. INS will approve AP and EAD, and your 485 follows a different route, your 485, will result in FP and tonnes of other checks possibly.
Once all your checks are complete, your application sits on a shelf collecting dust, until it comes in turn according to the WAC #, which is a function of ND/RD. So provided your App has cleared FP blah blah, your app is ready to be made decision on, irrespective of ur EAD/AP.
Now, might I mention, the turn according to WAC # is not very strict. Imagine a big building (ins's), with shelves all over and folders and bundles with lots of applications all over (yours and mine). Even the bathrooms maybe. They are put in an order with some dude's unfortunate job to make sure they are in order. Some of them are grouped in bundles, and within the bundles you have LIFO order. The bundles themselves are in FIFO order (mostly but not very strict unless some bundles fell over and killed someone and his dead body is hella stinky .. they'd avoid that bundle .. just kidding .. you get the idea).
Each bundle gets picked one by one, taken to an officer and looked at. The officer can either approve it or send an RFE, or send it to another officer. So depending upon all this, your app might be approved in 1 day of getting assigned or 1 year. therefore WAC#'s aren't a very strict order.
And meanwhile while all this happens, we keep praying hard, and our employers keep abusing us slaves. But as they say, if your only option is to get raped, you might as well enjoy it. So ENJOY IT.
Again, the above is my guess, not a hard and fast thing. use your own judgement (disclaimer). take care and good luck.