Glad things are working out Sue. You are doing exactly what you should about moving food bowl closer and letting the cat have her own comfort zone. You do not need to train her to get used to gun fire. She will on her own with time from your use see that it brings no harm to her. I have never known a cat that didn't run and hide from a vacuum. Mine even run when I use a broom or mop. Many cats do like to climb up high and usually can find their way down even if they whine and cry. It is amazing how far they can jump too without injury. They always land on all fours and their bodies are designed for it.

Keep up the good work! :-)