Ill have to read up on synchronised galactic field changes, but magnetic field reversal on Earth happens at least once every few million years. 

A reversal will suck, but I don't believe it would stop us using electricity, or even long-distance transmission. Induced currents would be annoying, but within tolerances for even distribution voltage. Venus has no intrinsic magnetic field, but it has an ionosphere and a weak induced field thanks to the action of the charged solar wind on its upper atmosphere.

Ditto for radiation - there'll be an uptick, but ten tonnes per square meter of atmosphere is a pretty good shield even without a magnetosphere.

Satellites would be f--ked completely, though...