Great post and really good questions, as a experience SAS Administrator I found these questions are suitable to test the canidate knowlege on platform administration, along side we can add some more questions on architecture, performance tuning, grid, VA, LASR, LSF will make it more strong. Many sites are now moving to grid and some are hosting their environment in cloud and also some of them are having thier databases on cloud, so adding loud related questions will also help. And we should never forget hadoop :) which is emerging very fast.