As for incendiaries, that was standard ordnance for any bomber aircraft during the war.
The point of incendiaries is to start fires. How can you then claim the Germans were "surprised" at the fires they started?
If the factories weren't the target, then far more than 500 civilians would have been killed in the attack.
Based on what? The Luftwaffe killed almost exactly 1 person per ton of bombs dropped that night.
Their long term average in the Blitz was somewhat less than that. The British dropped 657,000 tons on Germany, even if the USAAF never killed a German civilian, that's still less than 1 person killed per ton of bombs dropped.
The truth is that individual raids were very variable in the casualties they caused. The RAF's first thousand bomber raid on Cologne, for example, saw 1,500 tons dropped on the city, killing 474 people, and 36 factories destroyed (perhaps Cologne wasn't an area raid either, as so many factories were destroyed?) (all figures from The Right of the Line by Terraine)
What parachute mines? The 1/2KG antipersonnel weapon?
No, the 2000 lb naval mine, adapted for use on land, which carried a very high explosive content.
Either way only 100+ of these "air mines" were dropped on Coventry (some say 50). Not that large a number.
100 x 2000 lb bombs adds up 90 tons. That's quite a large percentage of the 500 tons of HE bombs dropped. The fact that such a large proportion of the bombload was deliberately made up of bombs that could not be aimed at anything smaller than a city shows that factories were just one of the targets.
The only other "parachute bomb" the Luftwaffe used was the SB1000 and that was used to penetrate armoured structures, like concrete bunkers. It wasn't a H E type weapon. They also didn't exist in 1940 IIR and only one per aircraft could be carried.
The Warbirds Resource Group doesn't list mines.