NetSuite's Mandatory appears to look at the Value attribute in a form element (radio button), it may be getting the value of the first radio button in a group, even if none are checked, and see there is something there. Because of this, I solved this issue with an HTML5 element and Javascript. I am answering my own question to help others with this:
HTML5 Approach:
The easy way is in HTML5 input fields have a new attribute called "required". Just add this to the end of the input tag and it will make the field required. Any HTML5 compliant browser will handle this. Example is:
<input value="Very Satisfied" name="custrecord208" type="radio" id="custrecord208" class="radio1" required>Very Satisfied
Javascript Approach:
Unfortunately, not all users use the latest browsers (HTML5 compliant) much to developers' dismay. Below is the code I wrote in Javascript for this particular problem. It may not be the cleanest but it got the job done.
function saveRecord_validation(){
//array of the id's you know you need to go through
var a_custRecNames = ['custrecord184', 'custrecord185', 'custrecord186', 'custrecord187', 'custrecord188'];
var s_quesNums="";
var isFormValid = true;
var isRadioChecked = false;
for( var i = 0; i < a_custRecNames.length; i++ ) {//loop through each mandatory customRecord
var radios = document.getElementsByName(a_custRecNames[i]); //get the radio buttons for that question
//reset isRadioChecked for each question
isRadioChecked = false;
for (var j = 0, length = radios.length; j < length; j++) {//loop through each radio button
if (radios[j].checked) {
// only one radio can be logically checked, don't check the rest
isRadioChecked = true;
break;
}
}
if(!isRadioChecked){
//cleaning up the output just a little.
s_quesNums = ((i+1) < a_custRecNames.length) ? s_quesNums.concat(i+1).concat(", ") : s_quesNums.concat(i+1)+".";
isFormValid = false;
}
}
if(!isFormValid){
alert( "Please answer question(s) "+s_quesNums);
return false;
}
return true;
}
Add this to the Online Form in NetSuite (for help visit NetSuite Answers: Attach Script to Form).
For help with creating Radio Buttons in NetSuite to begin with, visit NetSuite Answers: Use Radio Button values on Online HTML forms