> They send current pulses down the line to detect stuck switches, since stuck switches can cause collisions.

That's not done in any European rail network I am aware of. The switches have, well, switches that confirm if the mechanical end positions have been reached, but there is no confirmation by current pulses on the actual rails themselves.

> Also, the pulses are conducted through the wheels and axles of any trains, so they can use resistance and/or timing to figure out where the trains are.

That technology is, at least in Germany, being phased out in favor of axle counters at the begin and end of each section, partially because axle counters allow speed and direction feedback, partially because it can be unsafe - a single locomotive braking with sand may yield a false-free signal when sand or leaves prevent the current passing from one rail to the other.