I think the easiest solution may be to add a default value for opns1 to satisfy the required condition for when something besides "other" is selected.
<cfinput type="text" name="opns1" id="opns1" value="other" required="true" message="Please enter your choice" >
In your JS if (opval == "Other")
condition add
document.getElementById('opns1').value=""; // to clear "other" from the input.
in your form handler, check to make sure opns1 neq "other"
<cfif form.opns1 neq "other">
do something with the new value
</cfif>