Script to Perform Live Trace then in Illustrator Run Action... Please Help

I tried figuring out how to make a loop over the sub directories, but without any success .

mean while I add few things, I'm sure there is a better way to do it

1. a prompt to select folder (if there is a way to select multiple folders and/or files it might make it even more flexible)

2. each PNG is imported to a new layer with the name of the PNG. (but when i run it on my PC I get the space as in the file name as %20)

3. a Beep at the end of the script that lets you know it is finished. (I'm working on a different computer so it's very useful)

4. Import to single Ai file as I mentioned before.

and another thing, I'm using the Adobe ExtendScript Toolkit, and I couldn't find any way to auto format the script so it looks very messy, can you recommend me of another program or you know a way to do it?

AI Script will be perfect! THANK YOU so much for your help!

#target illustrator
while (app.documents.length) {
  app.activeDocument.close(SaveOptions.PROMPTTOSAVECHANGES);
}
var traceFolder =  Folder.selectDialog( 'Select folder for PNG files.', '~' );
if (traceFolder != null) {
var fileList = traceFolder.getFiles(/\.png$/i);
if (fileList.length > 0) {
     var ai = new Folder(traceFolder.fsName+'/AI Files');
     if (!ai.exists) ai.create();
     
     main(fileList);
     
} else {
     alert('This Folder contained NO PNG files!');
     
}     
function main(fileObjs) {
     with (app) {
     
          var orginalUIL = userInteractionLevel;
          
          userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS;
          
          
          var docRef = documents.add(DocumentColorSpace.RGB, 576, 720);
          
          for (var i = 0; i < fileObjs.length; i++) {
          
               if (fileList instanceof File) {
               
                    
                    var fileName = fileList.name.slice(0, -4);          
                    with (docRef) {
                         var myLayer = app.activeDocument.layers.add();
                         
                         myLayer.name = fileName
                    
                         var thisPlace = placedItems.add();
                         
                         thisPlace.file = fileObjs;
                         
                         var thisImage = placedItems[0].trace();
                         
                         redraw();
                                                       
                         thisImage.tracing.tracingOptions.loadFromPreset('Wave');
                         thisImage.tracing.expandTracing();
                         
                         redraw();
                    }
               }
          }
          with (docRef) {
                         var aiOptions = saveAsAiFile();
                         var fileName = fileList[0].name.slice(0, -8);
                         aiFilePath = new File(ai.fsName + '/' + fileName + '.ai');
                         
                         saveAs(aiFilePath, aiOptions);
                         
                         close(SaveOptions.DONOTSAVECHANGES);
                 
     }
     }
beep()
} 
}else{beep()}
function saveAsAiFile() {
     var aiOptions = new IllustratorSaveOptions();
     with (aiOptions) {
          compatibility = Compatibility.ILLUSTRATOR12;
          compressed = true;
          embedICCProfile = true;
          embedLinkedFiles = true;
          flattenOutput = OutputFlattening.PRESERVEAPPEARANCE;
          fontSubsetThreshold = 0;
          overprint = PDFOverprint.PRESERVEPDFOVERPRINT;
          pdfCompatible = true
     }
     return aiOptions;
}