Close the points of the micro switch and test for resistance across the switch. On resistance first then with the digital meter setting on the diode symbol. On this setting (the diode setting) the digits indicate voltage dropped across the points. The meter on this setting flows a bunch more current than the resistance setting and reveals bad connections more reliably than the resistance setting.I am using this switch in the circuit. Do you think that this could be the problem? It says that it is rated five amps. Does that mean that it can support up to five amps?
I think your main problem is the parallel wiring arrangement. If any one or two has less resistance for any amount of time for whatever reason then the current will go to the path(s) of least resistance and not leave enough energy for your dud igniter. Any of the six connections to the igniters can screw you up because of this.
I don't know why you think that in a properly powered series setup that the first will go off before the rest. Test those cheap *** camera strobe power supplies. They looked hot enough with all those sparks they showed on YouTube that I know I don't want to get across the leads.
I once got into an SCR scoop car capacitor without discharging it. I thought it'd blown off a fingernail. It would leave a pit in a screwdriver. I've never been hit by a flyback transformer but one of the older electricians said it was the worst shock he'd ever got. My worst was 300 VDC trolley wire to the frame of a mantrip from one hand across to the other. My muscles contracted so hard that I was throwed away and luckily broke the circuit.