The verdict re iOS and facebook is that it still doesnt work. I had another failed submission earlier this week, with a zipped simulator build that i had confirmed could be loaded fine in my iOS simulator using the steps that they provided in the FB doco. I have now been able to successfully get approval from FB of my features (publish_actions) by removing the iOS platform from FB and just submitting an android build for approval. (found this tip in another thread). Apparently you can then just add the iOS platform back in and it just works without getting approval, but im yet to confirm that for myself. (http://forums.coronalabs.com/topic/48204-submit-ios-simulator-build-to-facebook/)
The only possible reason i could imagine why they iOS simulator builds dont work for them is that somehow the way corona is building the simulator build is possibly locking it in to the local simulator (maybe certificate related?) and it wont work on someone elses simulator. Unfortunately i dont have multiple macs to try this on, so if someone else (maybe someone at corona) could give this a shot and see if they can get an iOS simulator build compiled on one mac to run on the iOS simulator of a different mac. (the instructions for running compiled app on simulator from command line are in the above referenced post, this is how FB try to run it apparently)