caveat,very long high temperatures aren't kind to tin or silver linings,so if you want to brown the top of a casserole or gratin that isn't in long enough to brown,no 450*f more than ten or fifteen minutes and the broiler is a no no for me
Yes, of course you can. Just do not heat empty copper pans above 425F
Yes, you can. In fact, you pretty much can put most cookware in an oven. Most cookware which you canNOT put in an oven have more to do with low temperature limit of their plastic handles or plastic knobs, and sometime wood, but that is less common. Even Teflon can handle 500-550 oF.
Aluminum, stainless steel clad, cast iron, enameled cast iron, carbon steel, clay, stone cookware can all be put in oven at a relatively high temperature. Yeah, I have a granite stone pot.
Look here is the thing, temperature of the stovetop stove is much higher than the typical oven baking temperature. As such, if your cookware can handle the stove temperature, its body has no problem handling the oven. The problem is that many modern cookware has low temperature silicone or plastic coating on the handles and the knobs. As such, this design works for stovetop, but not for oven baking.
So if your copper cookware for some strange reasons has silicone handle, then you will have to worry. Otherwise, you are good.