Ok. It seems that I've managed to do this (it took so long because I'm not using this computer very much lately). So as I've written previously, it seemed to work because I first logged into A (admin) account and then into B account. But if I was logging directly to B account after fresh start...
I've managed to do almost all what you want. I just don't know if the settings are taken from correct user.
I've added two tasks, using admin account: A.
One was setup to start when user A is logged in, using A account to log in and with "Run with highest privileges" (I don't know how this...