Can my remote controlled fan/light also be controlled with existing wall switches?
Nope, the HB fans have a single power wire, so only 1 switch will work. I had the same issue after installing some, and in the one place where it really bothered us we installed one of these https://www.amazon.com/Harbor-Breeze-Universal-Ceiling-Receiver/dp/B004FY8MR0 (essentially adding a second remote). In some other cases, we just replaced the dead switches with other things like USB charging ports or night lights.