PookeyMaster,
WRT reporting convictions, your observation is certainly valid and that in itself probably gives some weight to having a two year maximum validity on the card. On the other hand, if you are convicted and try to keep it quiet, you WILL be pinged at the next background check and can then be prosecuted against that section of the regs.
A lot of good debate on this issue eminates from these threads but unfortunately, that's where it stays and you'd be a mug to expect the government to act on what is discussed anonymously on an online forum.