Good Morning @wyre, thanks for you post on our Community Forums, and I'm sorry to hear of the faults on both the set top box and with the hub.
Can you possibly switch the hub off for 30 minutes to allow this to cool down.
When 30 minutes have elapsed, please plug this back in and reboot to see if the hub then performs without overheating.
If the hub does begin to over heat again, we may need to replace this for you.
In regards to the set top box, is it possible to reset the box and re-attempt the pairing of the new remote control to the set top box, to see if this will work for you?
Kindest regards,
David_Bn