I had many suggestions. Based on the feedback I received, I put together the initial list of questions. This list of questions can be change.
Instead of (or in addition to) configure dozens of settings, what do you say about a feedback adjustable control based on the existing system statistics and parsing logs (e.g http://pgfouine.projects.postgresql.org/index.html ) ?
Such an application improved with notifications would be useful for experimented users, too. A database is not static and it may evolve to different requirements. The initial configuration may be deprecated after one year.