Right, That is true that electrons don't really have physicality. They are in quantum field theory just probability of charge in the field.
This article was mostly a quick brain dump so I could finish something else.
I do still think that it would be possible to create an effect like the plasma window with a phased array and the correct patterns of interference. At this point I can't really comment on the energies it would take to stop something like a bullet. If I ever get to this project I will find out then. Plasma windows are able to with stand 1 ATM vs vacuum. Higher in some cases. As the Wikipedia page says though it would still be vulnerable to radiation like lasers and electron beams.