My sister got one of those real expensive pot for her wedding in 1954. She still has it and it still looks like new. I have wanted on like that ever since. So when I was 80 years old, I bought a water-less cookware set. I sooooo love it. Should have bought 60 years ago. And I do use my cast iron frying pans on my glass top stove. I think the thing that can happen is that if you drop them, the glass can break. I have seen a broken stove top.
As for using old pots and pans on a glass top stove, they need to be perfectly flat on the bottom. Take a ruler and hold the edge against the bottom to test it. If the bottom isn't flat, you are wasting heat.