Is a sanitizer needed when my Angular(2) app is only gathering form values?
I send those values to the server to validate it against my validation rules (no client validation desired) and if everything is valid and the user clicks on submit, I accept the form and redirect the user to a success page.
Which sanitizer are you talking about?
There is no need to sanitize the data before sending it to the back-end. Your logic will work without problemas...