The only way to avoid confusion
Electronics would be easier if we were made of antimatter
Being new here I am surprised anyone can have a confusion with it. Who cares in what direction electrons travel. Why bother with it? When you think of current you think of current and not electrons.
Perhaps my luck was that when I (at 10 years old) was learning the absolute basics of electronics, just like people when they defined the direction of current flow, I had no idea about the existence of electrons. Later when I heard about electrons I just took the information that they flow in opposite direction than current, and nothing more comes out of it.
I found at net first electronic book I have read:
https://archive.org/details/abc-radioamatora-c.-klimczewski-wyd-1953/ABC_Radioamatora_C_Klimczewski_wyd_1953_pdf_compressed/mode/1upThere are more pictures than text so not knowing the language you can imagine at how simple (understandable for a child) examples everything is explained. For example a filter is a hole in the fence through which the skinny ones (waves) can squeeze through but the fat ones cannot. Based only on this book I have build my first detector radio receiver.
I have an electron source, a container with a capacity of 1000 electrons(MINUS). I also have another container which lacks exactly 1000 electrons(PLUS).
Forget (as total as you are able to) about electrostatic when you try to understand electronic. The best would be like you have never heard a word about electrostatic.
In electronic negative or positive charge can't be collected in any single element. Any single electronic element always have no electrostatic charge. Your two containers in electronic have to be one element so even one has -1000 and the other +1000 they both being one element have no charge (if measured relative external world). Even in electrostatic having such two containers you can one load with -1000 and second with +800 in electronic it is not possible. Such element having these two containers inside it have to have at any time moment at them exactly opposite charge.
Normally we call something like this a battery.
In your model when half of electrons will move to the opposite container a potential (between containers) will be 2 times lower, but when from 1.5V battery you took half of its capacity you still have around 1.5V at it. So no. What you describe we not call battery. What you describe you can call Leyden bottle (in electronic it is capacitor).
When I connect both terminals together using a wire, current flows from minus to plus.
This sentence is true or false depending on what circuit part current you have in your mind, what we can only guess.
If you think (as I suppose) about current in the wire you used to connect terminals than this sentence is false - current in this wire flows from plus to minus.
But if you think (what I don't suppose) about the current in your element consisting of your two containers than this sentence is true - in this capacitor current flows from minus to plus.
In electronic current always flows in closed circle. As at each connection (in electronic net) along that circle there are different potentials and current in whole circle flows in the same direction than in some part of circuit current have to flow from plus to minus and in other parts from minus to plus.
Things begin to complicate when we came to AC (alternating current) when you can have phase shift between voltage and current. If shift is 90° then at the moment when voltage is 0 current has its maximum and when voltage is maximum current is 0.
I assume that it's better to place the load before the gate, than after the source.
This sentence I completely don't understand. Gate is used to control MOSFET.
Imagine a crane whose hook is raised by a motor that is turned on by a button. What you said is a consideration of whether to place the load in front of the button or suspend it under the hook.