The engine start + cable is a bit frayed where it joins the battery and smokes while cranking the engine, i am going to replace it but in the mean time is it a fire hazard?
Don't even think about leaving it. The connection is on its way to falling off completely. The very least that will happen is you won't be able to start your engine but if the end drops onto some metalwork you will end up on fire.
Also you must consider the effect on you starter motor. due to poor connectoin at the battery causing "smoke" your starter motor is suffering hardship and could also get damaged due to over heating during cranking.
Also there is a serious risk of the battery exploding due to gasses produced by the battery being ignited ...anyone who has ever seen or been near a battery exploding
will tell you they dont want it to happen twice..
Deal with your problem immeadiatly dont even think about it ..what you have seen (the smoke ) is your warning DONT IGNORE IT
had a peugot 205 ,just like that, but the engine wouldnt crank on start in warm weather. found out when somebody was looking under the bonnnet on a very hot day, and saw smoke & glow ! only one of the original strands broken , seem to remember there were about 15/20.
if ever there was a car built to a minimum price / quality