Really depends on what you do with the open phone. I can understand it being a huge distraction when watching video with the seam right in the middle. EBook reading? Apps in tablet interface mode? Might as well complain that using two monitors on your desktop is unusable because of the bezels. Doesn't matter in practice.

It's not that noticeable when you use the device. It will depend on your ambient lights usually and how you hold it. It's a lot easier to see when someone else is holding the phone too, so if that was your reference, you may want to use them a bit more first.

Dunno. Crease almost invisible when screen is on and not pitch black ( using Honor V3 while actual generation is V6).