Understanding Common Floating Return
My intuition is that (since these are 0V reference points, not actual ground connections) ...

Correct. The reference can be any arbitrary point on the circuit but battery negative is very popular!

.. if electrons flow out of the negative terminal of the battery there needs to be a connection to the right 'ground' in order to keep it at 0V relative to the left ground.

Don't worry about electrons. Just think of &quot;current&quot;. The grounds are all connected and at the same voltage.

Expanding on that, does that mean every 0V reference point can be thought of as being connected by a wire. So if I had 50 more 0V reference points, throughout some complicated circuit, all of them can be thought of as being connected? Thus simplifying any circuit with multiple 0V reference points to only one 0V reference point?
Question: What is the point of doing this? Is it just to reduce the complexity of circuit diagrams later on? Because right now it definitely complicates the one below.

Yes and it really cleans up a circuit, removes a load of wires and makes all the ground points instantly visible without having to trace &quot;wires&quot;.

Secondly, say instead of 0V reference points, those ground connections are actually earth ground connections.

English (as in UK / Ireland) practice is to use the word &quot;earth&quot; to signify a connection to the planet. Generally the earth symbol is used too.



simulate this circuit &ndash; Schematic created using CircuitLab
Figure 1. (a) Ground. (b) Alternative symbol. (c) Chassis. (d) Earth.

The reason why current would instead flow to the negative terminal of the battery is because it's more attracted to that then the neutral ground.

No. It's because current always flows in a loop. It's a bit like a bicycle chain in that regard.

Does any minuscule amount of current leak to ground?

To leak to earth two connections would be required so that current could flow through the earth back to the circuit.

Also, in the same sense as before, can we think of each individual 'earth' ground in the right diagram as connected?

Yes. That's the point.