This has absolutely nothing to do with shitty validation rules. It has to do with what you're outputting it as.
If you're outputting it to HTML, commas are fine. If you're outputting it to CSV, commas are bad. And your validation rules suck if you don't allow commas in any text field because it might be output to CSV someday.
Unicode RTL override can be dangerous in filenames (in the sense of confusing humans, not computers). It is necessary to preserve in content management systems dealing with bidi content.
Of course you can try to have different validations on your model, but then you need to make sure to know all output domains on the model level instead of doing it when handing over to the view.
If you're outputting it to HTML, commas are fine. If you're outputting it to CSV, commas are bad. And your validation rules suck if you don't allow commas in any text field because it might be output to CSV someday.