I don't have those problems. I used razer software without an account for quite some time (application just makes a profile for you, no username or password). I must admit - I don't use mouse buttons to change mouse from normal to hyperspace, so I can't help with that. 800 is fine for me, 16000 just makes my mouse unusable...
edit: I have a button on the bottom of the mouse for changing the "profile" and it's dedicated. By default, it also came with two buttons bound to + - DPI, I of course changed those to something useful (to me).