Hi,
This weekend I was studying the diference between a class,a structure,and another posibility that is only define a int variable(gMode), and define no_RC =0;RC1=1;RC2=2.....;
and I could use Mode names.
But the thing is allways the calc rutine will be stopping for do the micro second pulse count independently if this is needed or not, so I would try to implement all together and see what happend if I have problems I should try to use detachInterrupt;and see how many times I can use before arduino´s memory is full,and when this happend make a reset.