1. Who killed Sisera and how?
Jael killed Sisera with a tent peg through his temple. Judges. 4:17-23
2. Who was the judge during the time of Sisera’s death and who did they choose as military leader against Sisera?
Deborah, was prophetess and judge during that period and Barak (who demanded Deborah accompany him to battle) was the military leader at the time of Sisera's death, Judges 4:4-16.
3. Who was the judge who delivered Israel from the Midianites?
Under the leadership of Gideon, Israel was delivered from the Midianites. Judge 8:22-28.