I'd do a little debugging, if I were you, because it looks okay from here...
on *:OP:*: {
echo -a Enabled: $readini(FTCSounds.ini,Enabled,OP) -- Sound: $readini(FTCSounds.ini,Sounds,OP)
if ($readini(FTCSounds.ini,Enabled,OP) == 1) && ($readini(FTCSounds.ini,Sounds,OP) != $null) splay " $+ $readini(FTCSounds.ini,Sounds,OP) $+ "
}
See what values you have there and make sure that you have 1 and a valid sound. Just have someone be opped and see if what's displayed.
Just a note... I'd really recommend {}'s... but it's up to you.
Example:
if ($readini(FTCSounds.ini,Enabled,OP) == 1 && $readini(FTCSounds.ini,Sounds,OP) != $null) { splay " $+ $readini(FTCSounds.ini,Sounds,OP) $+ " }
Notice that I also adjusted the ()'s so there is one set around the entire IF and none around the individual $readini's. Your way isn't wrong, but it's better imho to write scripts following standard formatting rules.