“Meroz.” If this is a location, the location is unknown.
“Curse, yes, curse.” This is the figure of speech polyptoton for emphasis (see commentary on Gen. 2:16). There is also a sharp contrast between Judges 5:23 and 5:24 in that this verse starts with “curse,” while Judges 5:24 with “bless.”
“the mighty.” This refers to people, whereas “mighty ones” in Judges 5:22 is different and does not have to refer to people.