IIS7 Logging

First as a general rule I avoid putting the log files on the C drive unless I have no other drives available as C drives are generally configured smaller.  That alone would save you some grief down the road.

Now on to your question.
The logging you found does not control purging.  Rare as it may be there is no built in feature to purge log files.  What you are looking at is the basic configuration for logging.
The Log File section is pretty much what format, which fields and where you want the log files to be stored.
The Log File Rollover is basically states how often to create a new log file.

Check out the following links they may give you an idea on which way to go
Managing IIS Log File Storage
ODBC Logging <odbcLogging>

In a nutshell, how do I turn them off and what are the ramifications if I do?

I have never personally ever done anything with log files since 1999. But maybe the system does, so I don't know.

Also, if I were to move them to the docs server on S:
It would just be this change?
%SystemDrive%\inetpub\logs\LogFiles
to:
S:\logs\LogFiles

Once I change that, do I need a reboot? Will it mess up users who are online at the time? (After I deleted them the other day, weird things happened on the server and we did a reboot. Could have been a coincidence, but who knows.)

And I notice I can set it to Daily, Weekly, Monthly. If I set it Monthly instead of daily, will that use less drive space and be fine? What are the ramifications of that?

SOS (sorry so stupid)

thanks!