Hi, I am sorry to hear about these problems you are having with the watch. Whether you're using a phone, tablet, smart watch, or earbuds, all Galaxy devices have a set temperature range, where they operate at their best. While they may feel warm under certain conditions, like charging, this does not affect the device's lifespan or performance. However, if your devices get too warm, it could cause some issues. Use this guide to help keep your devices at their normal operating temperature. Give these steps a try: https://www.samsung.com/us/support/answer/ANS00076952/
Additionally, for the power issue, this could help as well: https://www.samsung.com/us/support/troubleshooting/TSG01003232/
Please let me know if this helps.