Yes the acetylene gas given off will explode under pressure in a sealed container. In welding / cutting equipment the gas is dissolved in a fluid to prevent this. Waste carbide that was still gassy, and new spare bits, would be carried in rubber "pigs" These would be a section of car inner tube (remember them?). The ends would be folded over and sealed with a rubber band also cut from the inner tube. The seals would blow off before a dangerous pressure could be attained.
The acetylene molecule has a triple bond, and burns inefficiently, the unburnt carbon soot would then glow incandescently in the flame giving a lovely light with a warm colour. The soot of course would get up your nose as well as on the cave walls! Acetylene has a garlicky like smell, and with the hiss of the jet and the pool of light you knew all was well
When LED light first arrived the diodes gave a very cold bluish light that felt very alien after carbide and halogen bulbs. The colour may still be cold but I guess we are used to it now