Like Bruce said, you can cut them off if you want to or leave them on the plant. It will be fine either way. I've never seen an orchid get any kind of infection from a cut so I don't treat cuts with anything. Whenever I have a tall blooming orchid in a plastic pot or very small clay pot, I temporarily place the pot inside a larger clay or decorative ceramic pot. That gives it a larger and heavier base which makes falling over less likely.