Maybe. If the GPU doesn't have any cooling at all then it can reach high temperatures quickly.

Can you see if the GPU fan is spinning? If so, is the GPU heatsink clean?

The mass of new USB devices that appeared is caused by you plugging it into a different port. Most USB devices don't have a unique serial number thats visible via USB so it can't tell whether its a new device or old device. The only thing it can do is assume that if you're plugging it into a new port then its a new device.