Pre-Chorus
The pre-chorus riff is very Vigilance-esque. Pay close attention to how the riff "resets" near the end of bar 7. The note sequence will be much easier to grasp by not biting off more than you can chew, or in other words, memorize the pattern in segments and then piece it together.
Chorus
These "5" chords with suspensions are very frequent in Threat Signal choruses. They open major possibilities for clean vocal melodies and harmonically still maintain a level of heaviness. The foundation of each is a basic power chord (root combined with it's 5th), with overlying harmony. These could be named as different chords, but for the most part, it's a tool used for occupying more rhythm section than a simple root chord, while another guitar offers a contrasting melodic lead part.
This technique is great to experiment with and will open the possibility of making 2 guitars sound like 4.