Nginx Error Log Reader is a php reader/parser/analyzer for Nginx error log file. the script is able to read error logs recursively then display them in a user friendly table. Script configuration includes the number of bytes to read per page and allow pagination through the error log . Additionally, table columns are sortable and full description of every error is displayed using MonnaTip.
For banning Ips, please refer to this post Using iptables to block ips that spam or attack your server
There not much performance difference between MYSQL 4 and 5 as far as you’re not using mysqli ext for your PHP scripts, but it nice to find rpms ready on Centos.org which makes the job much easier.