# Yahweh was putting his enemies under the soles of his feet
"Yahweh was helping David to defeat his enemies" or "David was busy since Yahweh was giving him victory over his enemies" or "Yahweh was enabling David to completely defeat his enemies"
# for the name of Yahweh
"in which people would worship Yahweh"
# because of the wars that surrounded him
"because of the wars with which his enemies surrounded him" or "because he was fighting enemies on all sides"