Batch scripting solution for illustrator?

if you want to do anything robust, you'll need javascript (or potentially applescript or VBScript... but both of these are very limiting too IMO). Actions are good for quick and dirty fixes.. they're horrible for any kind of robust automation, especially if any comparisons or conditionals are required. actions can't do either of these.

fortunately, what you're trying to do here is relatively straightforward. here's some pseudo-code:

//1. changing the font, size and color of text

//2. changing the stroke sizes, but there are 2 different strokes, one dashed and one normal

//3. changing the color as there are RGB when we receive them and we print in Duo tone (cyan + black)

var doc = app.activeDocument;
var swatches = doc.swatches;

var myBlackSwatch = swatches.add();
myBlackSwatch.color = new CMYKColor();
myBlackSwatch.color.cyan = 0;


//create a new character style with the attributes you want for the text
myCharacterStyle = doc.characterStyles.add();
myCharacterStyle.characterAttributes.size = 10;
myCharacterStyle.characterAttributes.color = swatches["Black"];
myCharacterStyle.characterAttributes.textFont = app.textFonts["Times-Roman"];

//loop all text frames in the document, and if they match a certain style
//apply myCharacterStyle to the frame
for each textFrame in doc
	var curColor textFrame.textRange.characterAttributes.color;
	if(curColor.red === 51 && curColor.green === 51 && curColor.blue === 51)
		myCharacterStyle.applyTo(textFrame)

//loop all the pathItems in the document and determine whether it's stroked
for each pathItem in doc
	if(pathItem.stroked && pathItem.strokeDashes < 1)
		pathItem.strokeColor = swatches["Black"].color;
		pathItem.strokeWidth = 3.5


//convert the doc to cmyk
app.executeMenuCommand('doc-color-cmyk');

As far as I understand your request, it can certainly be done with an action that you can then use in Batch mode.

If you can share at least 10 sample files , I or someone else may have a look at them.

Select Same Appearance works fine here. It selects either the dashed strokes or the solid axis lines