Mary Stella, the only thing I have heard about breads caving in is that something in the dough hadn't developed enough to hold its shape. Too much yeast, flour is too heavy, etc. Cakes will do the same thing with ingredients that are too heavy. I am afraid I am not one of these technical people who can give you this in depth jargon of the "whys and where's" lol. If a recipe fails on me, it might get a second try, but after that, out it goes!!!
I have never used glass baking pans. How do you like them??? For me, King Arthur flour makes all the difference in the world. I also love, love using part pastry flour in all my cakes, cookies, muffins, pie crust, etc. because it turns out a better product for me. I also love their SAF Gold instant yeast for all sweet doughs I make. I have a friend who does a ton of baking and she has converted to that also. K A is expensive but I do love some of their products and wait for the free shipping.
Sandy, all I ever use is the parchment paper for cookie sheets so the box works fine for me. Wilton has a baking spray out called Cake Release which I can't live without now. Nothing sticks when you use that stuff!!