About server msg's I have found doing that thru PB to be the best way, this way you don't need to have RCON programs up and running at all, it will all be server side.
Here is an simple tut on how:
1. Make a cfg file and name it servermsg.cfg
2. Add this to your pbsv.cfg file: pb_sv_load servermsg.cfg
3. This is WarTorn's servermsg.cfg:
//================================================================================
// Added by hugin - 2007
// Task setup for PunkBuster
//================================================================================
// 30 sec intervals - Remember: pb_sv_task 460 + 30 (Interval value) = 490, and so on
// Task setup for PunkBuster
pb_sv_task 10 490 "say message 1"
pb_sv_task 40 490 "say message 2"
pb_sv_task 70 490 "say message 3"
pb_sv_task 100 490 "say message 4"
pb_sv_task 130 490 "say message 5"
pb_sv_task 160 490 "say message 6"
pb_sv_task 190 490 "say message 7"
pb_sv_task 220 490 "say message 8"
pb_sv_task 250 490 "say message 9"
pb_sv_task 280 490 "say message 10"
pb_sv_task 310 490 "say message 11"
pb_sv_task 340 490 "say message 12"
pb_sv_task 370 490 "say message 13"
pb_sv_task 400 490 "say message 14"
pb_sv_task 430 490 "say message 15"
pb_sv_task 460 490 "say message 16"
//================================================================================
4. Then do pb_sv_restart in console or thru your rcon tool, or just simply restart the server.
5. Everything goes in your server pb folder.
Good luck :)