If human fear of being hurt by nature, and fears for nature being damaged both weaken our support system, Gaia, is that why, at least in part, the extraterrestrials use nature itself as a weapon against us?

This is very much the case. It is not only true that by making nature savage in very ingenious ways, it causes humans great distress and many setbacks for their well-being. The fact that it leads to deep inner fears and ongoing anxiety about the tenuousness of life, the unpredictability of nature, and its most dire consequences, serves the interlopers to keep humans off balance and drag them down. It certainly spoils the party in a very meaningful way and adds much darkness to their lives. Anything that undermines humans by making them worry, and fret, and live in fear, slows down human progress and diminishes human reach. Both are desired by the interlopers to keep humans subjugated and to glory in their own power to cause discomfort and suffering.