If you want to collect easily informations about a system, then I suggest you to test cfg2html. It will generate html and text reports with pretty much all relevant datas. If something is missing you are free to write your own plugin and add it to your reports.
Looking for an alternative to the daily used command df ? Sortable ? With color and other cool features ? Give a try to dfc.
etckeeper is a good utility to start tracking your changes in /etc. Of course you can initiate your own repo for your system but with etckeeper you will keep also the file permissions or the metadata.
# yum install etckeeper
You can now choose your favorite VCS, enable/disable autocommit, simply edit /etc/etckeeper/etckeeper.conf .
Want to know if something changed in /etc and is not commited ?
# etckeeper unclean ; echo $?
On a larger scale you will certainly want to use something more powerful to handle your configuration files (cfengine, puppet,…) but etckeeper is a good start and I’m usually using several alternatives just in case. 😉