Why is there a Patach under the Vov? It should be a Kamatz, for this is past tense!
Radak #1: We find like this - "va'Achasech Meshi" (Yechezkel 16:10). 1
Radak #2: Some say that it is because he lied. He did not kill him; he was already dead.
Why does Radak cite also "va'Eshpoch"? Perhaps the text should say "va'Echbeshech", i.e. he cited more from the above verse to identify it. (PF)
Why did he say "Ki Lo Yichyeh"?
Radak #1, Malbim: Since he fell on his sword, he could not live.
Radak #2: He could not live, for the soldiers on horses caught up with him and were close to him to kill him. He wanted that I kill him, and not that they kill him.
Why would a king take a bracelet and crown to war?
Mahari Kara #1: [Some say that] these refer to the Tefilin on the arm and head. The Targum of Etz'adah is Totafta.
Mahari Kara #2: The custom was for kings to go to war with gold ornaments, like we find the Midyanim who fought with Gid'on. The weight of the gold rings was 1,700, and there were necklaces and crowns, and ornaments on their camels (Shoftim 8:26). They took the crown from the head of Melech Amon in war (below, 12:30).