In My experience flying freight, I carried the whiz wheel in my kneeboard but never once used it,routes were predetermined, ATC will tell to to intercept ** or report ** GPS does all else. The only time I can think of to use it is running fuel critical due to heavy headwinds and needing to calculate fuel burn based on the altitude with the most positive wind. As far as wind correction, vor needles and gps pink lines fix that for you
The whiz wheel is great for VFR but the IFR environment is much more controlled. Thus have all things at your disposal for good crm but never stop flying the airplane to play with the whiz!!!
oh, and as far as the flight bag, carry the mimimal amont of crap as possible. Dont stop flyind so as to dig in an enormous womans purse to find something that you probably wont. Believe me, less is better!