BlockquoteI’m gathering the “sensitive business end” of the sensors is on their “flat side” as opposed to the “tiny tip”… Is that correct? It seems you have the opening sized to “reveal” the flat, large face on the side.
Here’s an image from the datasheet. You can picture poking the 3 prongs into the ground and looking down at the part. The taper points to where the sensor is. So you want the taper pointing to the south side of your magnet.
Blockquote 1. do I connect to the two outside leads/wires, isolating the center lead/wire?
Ground should have a capacitor between it and your voltage, and output should have a resistor between it and the voltage.
Blockquote 1. does it matter which lead/wire gets attached to what? Or do I have to be careful, treating the thing like a “one way only” type device?
Yes you can think of it as a one way device. Output and ground cannot be swapped. The device needs the relationship between vdd and gnd established for the switch to work properly and allow output to be pulled down.