Is it possible to skip the line by purchasing a online ticket?

No and don't buy the "sunset" tickets if you want to see the sun set. They don't let you up early and the line takes so long you'll miss it.

The VIP ticket allows you to skip all elevator lines up to the Top and down; it also allows you to enter anytime on the date it's purchased for, no need to chose the time ahead of your visit.

You can skip the first line if you have a ticket already. Also if you have a vip then you can skip most of the second line. But there is not much to skip.

No. Its not that much line. They sent lot of people at one go.

Not possible to skip the line.

You get a specific time to enter the deck by booking online. You can choose the time by yourself online.

Only the first line