Jan Panteltje wrote:

So, if you keep the frequency constant and increase the amplitude
(use light of higher intensity), then at some point you should
reach the threshold acceleration and, therefore, electron emission.

No I think not, the thing will release on a speed CHANGE (direction
change)

speed change (direction change) = acceleration


What I am trying to do is somehow come to some interference of
De Broglie's wave with the incoming light.

I don't understand where are you trying to get with this.
The photoelectric effect has been understood by quantum mechanics
decades ago. There are theoretical formulas and numerical algorithms
that allow you to calculate anything you would like to know about
this experiment with very high accuracy.
It seems that you are not happy with these
standard approaches. You are trying to substitute them with
some "classical" explanation of photo-effect as shaking the electron
by variable electric and magnetic fields. Then don't use
"De Broglie's waves" because they belong to quantum mechanics.

Personally, I don't think you'll succeed here. This chapter of
physics has been well understood and closed.

Eugene.