yes you generally tune your oscillators and then the v/oct is added - if you want to change the root note you would use a precision adder or some other modules that has that functionality
Not shaking my head at all - this is all a very personal journey - especially not on module choices or number of voices or cases - there are no bad paths - some are just more expensive than others
you seem to know what you want and have some idea of how to get there - time to grab the case and a few modules and start on your journey - go slowly if you can (learn each module as thoroughly as possible) and don't worry about not sticking to the plan
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities