No the reason would not be for lack of pay stubs but for actual need.

Yes you may travel with your valid passport and extension receipt notice.

Best to wait the decision before being concerned.

A review of your case is needed to provide support and guidance.

I agree with my colleague re: indications.

Yes they may apply despite your status.

It depends on the specific facts of your case. Consult with an attorney for guidance.

Yes you do not have to indicate beneficiary info other than passport if not in US.

Not normally requested but officer may have had reason since what he indicated was changed facial features.

Yes it can take up to 120 days post interview for decision.