I like to have two (or more) different XFCE sessions for one user which have differences in autostart programs, panel design and others. Is it possible to make that, are there profiles for XFCE? (For LXDE, there are) How can I set / switch between different profiles?
I am not sure whether the settings that you want are user- or session-specific. You can try and see.
In Settings Manager - Sessions and Startup - General: check 'Display chooser on login' so as to be prompted after login to chose between your Xfce sessions. To save a certain session, you can save it manually ( Settings Manager - Sessions and Startup - Session) or check 'Automatically save session on logout" (Settings Manager - Sessions and Startup - General).