As soon as you open QLab the machine switches from the integrated GPU to the discrete GPU. There was a problem with those affecting 2010 MBPs, and the next generation of MBPs have just undergone a recall to fix heat-related issues with the GPU. My 2011 machine runs a lot hotter when using the discrete GPU – although it is not as hot as it was now it has a new logic board.
So, a fair test of whether it's QLab or not will be to compare it with just having iPhoto open – which also switches the graphics.
An SMC reset is worth a try too – if the battery doesn't stop charging when full the machine will get hotter. Again, my experience was that I had to unplug the PSU as soon as the battery was charged until I had the logic board replaced.
You can't knock a basic stand to increase airflow across the bottom of an MBP either.
As for licensing, we seem to cover that at least once a month here. A quick Google brings you to
http://figure53.com/qlab/docs/licenses/ (although rather depressingly it tries to auto suggest cracked copies of QLab too: scum).
What are these temp files, by the way?
Rich