i can only answer to a few of your questions:
2: Osc fatness is indeed a stack of detuned osc voices. At the moment there is no modulation possible for fatness and the related parameters. But a work around might be to use mutiple osc each with fatness=2 (=3 voices, center/up/down pitch), different detune and osc pitch modulated. As the number od osc is not restricted, you can even build the Roland supersaw by 15 seperate osc
3: I have no idea about Jo's plans about scripting, but i am already impressed by what is achievable with the current means! And don't forget, you can use any VST in a Mux.
5: PWM is a straight saw wave with the AIPS modulated. Results in an exact PWM
