Question: is using hotspot bad for your phone?
Answer: Yes,the use as hotspot uses much more current than normal mode. Essentially you are using the phone as router, and WiFi+3G routers use up to 2A at 5V when in full use. That means for example, that a 2000mAh battery will last 1 hour at a 2A drain rate. To minimize use of the battery, you can keep it charged trough USB.