1)
What is "Evrah"?
1.
Malbim: It is general anger 1 .
1
Malbim (Bereishis 49:7): Evrah is anger that passes the border, and strikes even those who did not sin.
2)
What are "Sho'ah" and "Mesho'ah"?
1.
Rashi: Sho'ah is an expression of desolation. Mesho'ah is greater desolation. Radak - the entire verse is repetitive to strengthen the matter.
2.
Malbim: The affliction will come suddenly.