As to the "flow of electrons" - if you have a line of 100 marbles, take a marble out some where near the centre. Move the marble from the left of the gap to the right and repeat the process.
Which way is the gap going? ( +ve holes?)
The electron moves one space and has an influence on the next to move a space but overall electrons do not travel.
This is how a semi-conductor conducts, not true for metals.
In a metal crystal all the electrons are de-localised and free to move. They will move around at random due to heat, if an electric field is applied, the electrons will still move at random, but will have a drift in the direction of the applied field. The mean drift velocity is what we call current.
also it is very difficult for an electron to exist on its own
Quite easy to do this, all you have to do is heat the metal in a vacuum, some of the electrons will have enough energy to leave the surface of the metal and form a space charge above it. If you the add a second cold electrode, you have made a rectifier valve.
. I think RFID tagging is worth a go and if it works, we can introduce it to equipment libraries.
me thinks.