Kitz suppressing the evidence is due to direct alien involvement.
"Yep, Humanity isn't ready yet" was their report. As a result they notified certain government officials to suppress the evidence for x amount of time, until Humanity is ready for another evaluation.
Ellie and Matthew are BOTH right.
The Vegans are hideously ugly.
Another reason why one of them appear as her dad since they don't want to scare her.
The shimmering dots represent known habitable star systems.
Earth is one of them, and the rest are ones that made contact with the Vegans.