Stars falling from the sky are referred to in Daniel 8:10, Matthew 24:29 and Mark 13:25 as well as Revelation 8:10 & 11. Daniel chapter 8 seems to be the most relevant here; especially note verses 23-25. This may shed some light on the political environment at this time.
The first reference to lamp or torch is Genesis 15:17 right after God foretells what will happen to Abram's descendants. The second reference is Judges 7:16. Chapters 6, 7 & 8 of Judges maybe especially relevant here - where the Lord uses Gideon to lead his people. Also note Isaiah 62:1.
In the King James Version the first mention of wormwood is Deuteronomy 29:18. The renewal of the covenant in chapter 29 and prosperity after turning to the Lord in chapter 30 maybe especially relevant here. Also note: Jeremiah 9:15, 23:15 and Amos 5:7 (seek the Lord and live).
If the death and destruction during the first and second trumpet was from volcanoes, then there is a good chance that a volcano is the source of "a great star, blazing like a torch" that fell from the sky. The same, or similar, poison that killed creatures in the sea would kill people from the "bitter" water. Exodus 15:22-27 maybe relevant.
"the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter." (8:11).