Since the TH-32ES480DX is widely sold in India, the primary source is:
Panasonic India usually hosts the firmware for this specific model. Panasonic Th-32es480dx Software Update Download
A: Usually no. Most Panasonic firmware updates preserve picture settings, channel lists, and Wi-Fi passwords. However, a backup is never a bad idea. Since the TH-32ES480DX is widely sold in India,