You can probably get a new belt either at an old hardware store or on line.

The GE motor on your dryer is newer than the machine, so it was likely replaced at some time, I would not worry about oiling this motor they were very good motors.

You can use the white lithium grease on the shaft of the spoked pulley and its sliding shaft. You can also look at the top of the main drum bearing tube and see if there is an oil hole and add light oil to it if there is one.

The Hi-Low temperature Sw does look to be by-passed, it basically reduced the heat input by switching more or less of the heating element in the circuit, it is probably not that important the dryer will still get just as hot on either setting.

John L.