Is there a easy way to turn off the "If you are having problems connecting due to ping timeouts, please type /quote pong 45C45823 or /raw pong 45C45823 now." message when a user connects?
Correct. Assuming you are not using an >4 year old OS: Linux, FreeBSD and stuff are all safe.
Windows is absolutely not and I can spoof "any" IP I want within a few seconds till a few minutes depending on my connection speed :P.
[removed previous reaction due to very bad advice]