Jellycopter

Hi all.  I'm a new member of the forum, and pretty much researching pyrotechnics for the first time.  .

My field of education is mainly in music/audio/programming/game development, although recently I've been working with electronics as a hobby.  
I was working on a particular project this week which involved discharging a large capacitor, causing a huge spark.  I became interested in designing the same sort of spark in a device triggered by a button, which inevitably lead to me raising a discussion on the electronics forum I use about how to create such a device safely, how to control what the spark looks like etc.  
One particular member said I was describing a weapon, however I had a video reference to a device used on one of my favourite TV shows to use as an example of what I really meant, which is a sort of theatrical prop.  See this video at 12:00 



Long story short I have been redirected to pyrotechnics!   
So with my background in mind, I'd like to ask a few questions...

1)  Is it legal in the UK for me to build a device like the one shown in the video?  Does it qualify as an explosive?
2) There seems to be some distinction between theatrical/cinematic effects and fireworks regarding laws on explosives.  Do I need a license or certificate to start dabbling in theatrical props such as a handheld device that projects a short flame burst for e.g?
3)  What sort of professions exist in this field?  I know of stage technicians and firework 'firers' so far.  
4) What I'm really interested in is designing things; what would I have to study in order to understand the inner workings of these effects, to the level where I can be creative with their design?  
5)  Kind of the same as question 4, but outside of this forum, how/where is one supposed to find learning resources?  This whole subject is shrouded in mystery...
6) What sort of educational background would you require to be taken on as an apprentice by a fireworks company?

I have tried to find these answers myself, but have found the results quite ambiguous.  I'm really interested in learning more about about pyrotechnics though, and I'd just like to make sure I go about this the correct way.  To clarify, I'm interested in building my own small scale effects simply to educate myself in their design.  I'd also like to experiment using my own electronics controllers to trigger/ignite these effects.  I don't have any particular agenda other that to learn how it all works at this point, but perhaps some day I'd be interested in a career involving the design/manufacture of pyrotechnics. (Triggering systems and musical synchronization might be a way into this industry for me, given my background).