I have the seam also, I noticed it like you did. It appears to be the removable liner is attached behind the seam. But, it doesn't impact the fit or function of the helmet, so I guess that's ok, it's just a production thing.
This is the visor, as has been mentioned, there is no tab sticking out to raise/lower it. It just takes a little getting used to, it's easy to work the shield as is.
My new helmet next to my old helmet. Anyone wanna buy a really clean RF1100?