Under your criteria, most polymorphisms would be neither normal or abnormal but rather undefined.
If it were up to me, I would use the term mutation only when the allele was known to cause or was suspected of causing abnormal function; i.e. polymorphisms in your undefined group would not be referred to as mutations even if they satisfied the <1% threshold.
Perhaps this discussion of terminology has exhausted more bandwidth on the message board than it deserves, but I found it instructive.