Hi Enkil
Well, I'll try to answer them as good as i can - but i'm not 100% sure of it all...
1) Pyrotehnics is a generel term, that includes fireworks, the blast-devices in airbags and a lot of other things we don't know excist many places in our everyday life.
To say it in another way:
Pyro= Fire --> Firetechnics... = Everything that makes a reaction based on some chemical mixtures... And fireworks are one of these niches.
2) I would call if fireworks, because you pahaps could be mistaken by some freaky professor

If you use the word fireworks and pyromusicals i'm pretty sure you should make your point.
3) Advantages: Entertainment, universal joy regardless of age, origin, skin-color etc. It brings people together. The "Karma" of fireworks is to make people happy and that's what i like about it
Disadvantages is like you mention the pollution and that it can bother people who don't like it...
Regarding a system to make no smoke, many people has probably been trying to solve it...
Pahaps it could be possible to mix a chemical to purify the formulas? It would probably be very expensive, and therefore nobody would buy them... Money determines virtually everything in this world today
4) I have never spoken a word french so i can't help you there
5) That depends if you're running timecode through a DAT-player. In that case yes, because there is a track on the tape only for information about the firing-cues. But if you run it seperately the firing module naturally will continue - so hate when it does that
I hope this could help you? If you want more detailed answers let me know and i'll try... But regarding the chemestry in it i'm not that expirienced, though
Regards,
Lars