1. You are missing such operators like || and && (former is string concatenation, latter is tests overlapping geometric objects).
There are also a. math: !, !!, #, >>, <<.
b. geometric: ##, @@, @-@, ~=, <->, &<, &>, <<|, |>>, &<|, |&>, <^, >^, ?#, ?|, ?-|, ?||, @>, <@.
c. network: <<=, >>=.
?| is both binary and unary operator, ! is postfix (but is equivalent to prefix !!, so you may define :! that expands to prefix !! or just :!! that expands to !!).
There are also another operators like @, but they have functions-substitutions (@ x <=> abs(x)).
psql's command \do (describe operators) also lists other operators.
2. As PSQL allows defining own operators, I think it worth exporting s-sql::def-infix-ops or creating some more flexible user macro (one might prefer to use :concat instead of :||).
With such facility you don't need to define such rare-used operators like @-@ and ?-|, allowing user to define them.