I am working on a web app with a sign up form like below. The validations are all done client side using http://formvalidator.net/.
I am well aware that client-side validations can be bypassed, but I have currently not bothered to implement server-side validations as they are much more painful to implement and require procedural logic in the html and so on.
My reasoning is that there is actually nothing here that requires server-side validations, no file uploads or data of great importance that absolutely must be correct. If the user gives the incorrect email address then they will never receive their confirmation email, if there name is incorrect that is insignificant, and so on.
Are there security problems with what I am doing?