Is TONIGHT the final or tomorrow night?
 

If tonight is, how are they gonna do the voting and results? Have a voting gap filled with guest performances?

Both.

I beleive fourth place is announced tonight, and three progress to tomorrow's show.

what are they gonna do in the gap between the voting lines opening and then announcing the eliminee? if that's even a word, and two are leaving tonight. it says on the description.

Tonight, as all these four acts are in the finale, but they'll get rid of one and have three for tomorrow night.

The lines will probably open after the acts perform their first song.

Then after the second songs, an ad break an maybe the group performance of the ****e singers that didn't make it through, then another ad break?

The lines will open after the first performance, after the last second performance, there'll probably be an ad break, then the lines will close, a performance of some sort, and then either the results or another ad break and then the results. That's how I'm seeing it working.