I don't think pulseaudio autostarting is governed by alsa. There are two options you can try.
1. disable autospawning through configuration. For that, try setting the client-conf field of the pulseaudio-configuration to '((autospawn . no)) 2. Removing the pulseaudio package from gnome and anywhere else it might be propagated. (I don't think it is propagated in other services). Regards, Leo
