Good reply, but..

Regarding 1: In the article, they describe an antenna that is MORE sensitive than the normal antennas. So you may not be able to detect the low frequency radio-waves without a similar sensitive apparatus.

Regarding 2: There is the problem that Electric signals can have high similarities with the "Chirps" that LIGO is looking for. For example: even in space, you can find all kinds of "chirps" caused by solar plasma. google "noises from space".