Matt, that's what I was getting at. I might be wrong, but I'm pretty sure these days it's a lot more specialised than that.
The dude designing the performance is not necessarily the same dude that is orchestrating the performance as it happens. But in some cases it may be.
For example, on one of my music DVD's, in the crew credits, there was pyro designers and pyro techs. (I checked this cos your question got me interested!)
If you're looking to make a full time career out of it, you are probably looking at larger scale stuff in Australia as the use of pyrotechnics is so tightly regulated.
The larger scale stuff would be designed using computer models with a basis on physics principles I'd assume.
I couldn't find anything anywhere on courses in pyrotechnics. I'd hazard a guess that there is not too many people in full time employment in that industry in Australia.
But if you stick to your maths and science and IT subjects you should be fine. (IT for design and you'll find most of the performance is operated through computer systems.) Chemistry is the big one because after all that's exactly what pyro is... chemical reactions.
A lot of it may be industry based training as opposed to formal courses. But I'd assume there would have to be some type of science background required.
This is what I sort of knew off the top of my head and what I could find by having a quick look.
Happy to be corrected if I'm way off the mark.