[b][color=#282828][font=helvetica, arial, sans-serif]"a) Is a gig bag a good place to keep the bow for protection?--or to buy a bow case?" [/font][/color][/b]
I would always recommend a bow case, it's way to easy to damage the bow if you have it in the bow pocket of your double bass case. However, if you are not traveling with your bass much just use a parcel tube.
[b][color=#282828][font=helvetica, arial, sans-serif]"Do you have more than one bow?"[/font][/color][/b]
[font="helvetica, arial, sans-serif"][color="#282828"]I have one German which is my main bow that I've used for pretty much everything I've done...I've also got a cheap French bow for teaching. [/color][/font]
[b]"[color=#282828][font=helvetica, arial, sans-serif]Would a pro. classical bassist rosin their bow several times--say for a 2 hour concert?" [/font][/color][/b]
[font="helvetica, arial, sans-serif"][color="#282828"]Too many variables, but most would add rosin at the start of the concert... possibly at the start of each half if it was in two halfs... there's too many variables to say for sure though... Generally I would advise being sparing as new students often add too much. Here's a video where myself and Lauren Pierce discuss this. [/color][/font]http://discoverdoublebass.com/lesson/what-double-bass-accessories-do-you-use-ask-geoff-lauren-15/