Greetings, Soukyuu!
Thank you for your patience with the wait for a response to your report. After thoroughly inspecting this matter, the development team has found what you have describe to be the proper function of hitting the ALT+TAB keys at this time. However, they are currently looking into addressing this function in the future, so I highly recommend consulting http://lodestone.finalfantasyxiv.com/ for any further developments. Thanks again for the heads-up!