[eluser]TheFuzzy0ne[/eluser]
I still don't understand the question, but I'll try to answer anyway.
AJAX is no less safe than using a Web browser and clicking on links. It's pretty much identical (it even uses the same cookies during a request), the only difference being that it does all it's work behind the scenes. So long as your app is secure, you have XSS enabled, and filter user input, all should be well. Imagine AJAX as being a Web browser in it's own right. It can send data to the server, and retrieve data, just like a Web browser. A lot of people may disagree with that analogy, but with regards to security, I think it's fairly accurate.