My Seq screen is flickering slightly, periodic. Is this normal?

Yes, this is normal behavior. The screen is flickering in all of the existing manufactured devices due to hardware/software related decisions we've made while making it. There's nothing we can do about it now, yet it is not anyhow influencing the workflow. The Seq is our second instrument, we're still learning. If this is disturbing you badly - the USB powering should be less bright and less annoying.