Think cellphones and leaky microwave ovens and
a hundred other devices that use microwaves.
I think the danger of microwaves are over-rated.
(An asteroid impact with Earth could kill a lot more people,
theoretically, than microwave usage on Earth over a
period of, say, 1000 years.

As far as microwave dispersion and absorption?

Think of the MASER!....Invented in 1954, it has been much
improved since then...
The best way to think of the maser is a variation
of the laser, but instead of EMR at visible-light frequencies,
you have EMR at microwave frequencies.
The beam dispersion for masers/lasers/ is far...far...far less than
that of a parabolic-dish transmitted energy 'beam'.

The best place on Earth to place microwave receiving
antenni to pick up thje beamed energy from GEO for energy conversion into electricity is in the dry, isolated Atacama Desert in Chile/Bolivia.
[Death Valley, California isn't a bad energy-beam reception spot either.]

What I propose would be an international project;
certainly America couldn't fund it alone.