To check the games ticrate you can use a program like HLSW and in the console section type:
sys_ticrate :then press enter. (remember to enter the server details and the rcon password for HLSW to work properly)
scrollmsg is the message that scrolls accross the bottom of the screen in game and imessage is the message that appears just above the middle of the screen in game.
To setup these messages make sure that the scrollmsg.amxx and the imessage.amxx are running in the plugins.ini (no ; in front of the plugin) and then adjust the values in the amxmodx/configs/amxx.cfg
Code:
// Frequency in seconds and text of scrolling message
amx_scrollmsg "Your message here" 600
// Center typed colored messages (last parameter is a color in RRRGGGBBB format)
amx_imessage "Your message here" "000255100"
amx_imessage "Another message here" "000100255"
// Frequency in seconds of colored messages
amx_freq_imessage 180
You can change how often the messages appear, add more imessages and change the colours of each message also.
Hope this info help