This is a very interesting thread, but I don't see the relevance of some of the questions, like:

How much memory does SQL use on startup?

I've never had to share an SQL Server with something else, and I rarely start them up.  On the other hand, I'm very interested to know what someone thinks of NULLS, referential integrity, where should business rules be stored, mud tables, when to use cursors, when to use views, and so on.  These questions may not always have a right answer (though some I think do) but they will go a long way to determine fit in the organization.

I did once, however, had a interviewee who told me he had a lot of experience with SQL triggers.  When I asked him to describe one of his triggers and what it did, he said that he wrote a program that, when the button was pressed, "triggered" the database to do something.