I'm guessing the bearing header is above the top of your opening and you are looking at a framed in filler to lower the top of opening. You could check to see if there is a solid header above by driving in nails 4-6" above the bottom of drywall.

We have no idea so get a pro to tell you not a bunch of strangers on a site.To me it looks like it could be.

You don't go by the exposed framing, you go by looking in the attic to see which way the joists/trusses are going. Parallel with the exposed wall, non-load bearing; perpendicular, probably so.