1)
Why does it say "Socho"?
1.
Radak (48) #1: This is like Sochaso. We find like this [that the Sov is omitted], e.g. "v'Tzuram Levalos She'ol" (Tehilim 49:15).
2.
Radak (48) #2: It is from the root Soch, like the word form of Bor (a pit).
