cpk, ckp= crank position sensor, cmp/cmps=camshaft in tech acronym jargon.
i get confuseded sometimes myself, so i look for the 'm' or 'k'. cam will be designated by the 'm', the crank by the 'k'.
and no, the car will not start without the crank signal. it will run poorly, though, if one if out of spec.
the cam position sensor is just for a synch signal to identify the #1 cylinder.
thanks for the update on this though. it'll help wihen others may be searching for answers to similar issues.