OK, I tried all three, and here are the results. The first one, which was:
//echo -a $readini(FTCSounds.ini,Enabled,OP) -- $readini(FTCSounds.ini,Sounds,OP)
Resulted in NO sound and the following on screen message: -- C:\Program Files\FTC Chat Commander v.6.2\sounds\op.wav
OK, that doesn't show anything for the first readini call - $readini(FTCSounds.ini,Enabled,OP)
Check the ini file for that setting, either the section name or item name is wrong or its not set.
Your script relies on it being set to "1" (without quotes)