You can connect a USB mouse and HDMI simultaneously to your device using the 5 port hdmi connection kit
.
Remember to connect in the following order.
1. Power the connection kit
2. connect the kit to your phone
3. connect the mouse
4. connect the hdmi cable.
My phone screen was completely damaged. That was the only way I could enable usb debugging. Now I can view the screen from my computer via usb and use the mouse and keyboard. This was done on Samsung Galaxy S3 LTE version I9305
Best of luck.