Postmaster options, process spawning, logging, etc.

Greetings,

Sorry for all the posts, but I'm trying to put my finger on my backend crash.

Any insight on any of the following would be very helpful:

How many backend processes is considered a large number?  The man pages
says the default is 32.  Does anyone set their number higher?

Kind of related to the question above; when does the postmaster spawn
another backend process?  Is it for each additional connection, or will
each backend process handle several connections/queries before another
process is started?

The postmaster log file, why are the entries not datestamped?  If I start
the postmaster with a debug level of 2 or greater do I get datestamped
entries?  Also, what is the highest debug level and how big can I expect
the log to grow?  Can I rotate the log without stopping the postmaster?

What is the pg_log file in the data directory?

What are the major system resources used by postgres, i.e. semaphores, file
handles, mbufs, etc.?  I'm trying to determine if I have my resources
configured high enough for my user base.

Again, thank you!  I'll try not to be such a problem in the future! :)

Matthew