But that's simply not true, disclosingshite. Rare, but severe complications can arise from both mumps and rubella. You'd have to be really, really unlucky but it happens.
Equally, severe complications from vaccination - the life-changing complications that you feel aren't worth the risk of exposing your dds to in the case of MMR - are very rare. You'd have to be really, really unlucky to get them.
My feeling is that the second risk is much less likely to happen than the first (of course the odds are that neither would happen most of the time). You have calculated differently.
I'm just interested in why you've made that calculation? I have a mumps-damaged member of my family (older generation) and suffered very severely from mumps myself, taking weeks to recover (pre-MMR) so mumps damage feels quite real to me. I probably overestimate it because of my personal experience. Do you know someone who is vaccine-damaged? Is that why you calculate the risk as you do?