I think; Exterminate them, they were useless in their eyes weren't they? Edit: Oh I think I've misunderstood your post..
of course,not all able young men were drafted in the army before and DURING the war (as in all countries):engineers and doctors were not called up till they had finished their studies.And,the irony is,that during the war,proportionnally,LESS men were called up:specialised workers,fire brigade,railway personnel,etc,were not called up . about the objectors (there were few of them):before the war,they were not shot,during the war:maybe,at the end .
From the book Frontsoldaten (if memory serves right), you were only exempt from duty if you showed some sort of an illness, something that couldn't be cured short term essentially. There were punishments for those who objected to things like the oath. I'm trying to find the specifics but so far, nothing on the punishments themselves. I had a link but I seem to have lost it. One example is of Franz Jägerstätter who objected and was shot. Franz Jägerstätter - Wikipedia, the free encyclopedia I guess it would have seen as a form of desertion?
They only started to use Conscription when the tide of war changed, by 1945 they used people from the ages of 12-65+ I think people more volunteered than conscripted in the Nazi Army, I mean they often told POW's: Concentration camp or Join the Army (didn't apply to the "lesser" races of course)
I believe that both the current Pope and his brother were given waivers from the Hitler Jungen when it became mandatory so they could continue on in their seminary studies. It wasn't until the final year (1944) that he was drafted into an AA battalion, from which he promptly deserted. If he had been caught he would have been hanged, like any other deserter.