I have a Yoshi TRS on my Bandit and yes, you could run without jetting it, but let me tell you that you will be wasting your money by just going with a pipe. I have the "Race" version TRS can on mine and still love it after 3 years.
I have Ivan's kit jet kit in mine, and with the combination, it is an entirely different bike.
Now The Snorkle.
The snorkle is there to create velocity in the airbox. (especially at low RPM) Removing the snorkle takes away from low RPM power, but does increase high RMP power. Even with my moded airbox, the snorkle makes quite a difference. The bike is boggy in the lower RPM range.
Think of it this way. Carbs work on vacuum and in order to create vacuum you need resistance. (it's a balancing act to get the optimum air/fuel combo right) Removing the snorkle without jetting the already too lean Bandit will make you run leaner. You will actually loose power by doing this in my experiance.
I do know of sevral people that took a stock Bandit and went up 1 size on the main, Pilot & shimmed the needles. That just shows you how weezy a stock B-12 is.
More air is a good thing to a point, but if you don't increase the amount of fuel to go with the air, you are actually taking a step backwards, if you have a minimum amount of fuel to begin with. (If that makes sense).
For The record.
Bandit Quarter mile time 10.98 @121.9 mph
Busa Quarter mile time 9.88 @ 143.88 mph
According to MC magazine