Lodi was a busy place years ago. During grape season, over 100 reefers would be loaded a day at a number of fruit packing sheds in town. General Mills would generate 20 or so car loads outbound and get several cars of grain in a day.
In partial answer to your questions:
1. There was a yard across from the station, a double ended compound ladder one. There were at least ten packing sheds around the yard.
2. The Woodbridge branch served General Mills and several packing sheds and at least one winery in Woodbridge.
3. The Kentucky House branch served several packing sheds between the SP main and Hwy 99 and an oil dealer. Outside of town, several more sheds were served and the branch extended to the Calaveras Cement plant past San Andreas. Normal cement plant service, a few cars in and loads out, boxcars loaded with sacks of cement and later hopper cars with bulk cement.
I believe from talking to an old SP employee, they had 3 crews assigned to Lodi in the 1950's.