I shoot my blazers through a WB and use a right helical. The benefit of helical fletched arrows is the fact that it promotes spin, as you pointed out. However, the cause of the spin is the friction w/ the air after the arrow is released. The 5 to 6 inches between string and restwon't reduce the amount of spin you get. I also feel that the helical doesn't cause enough extra friction w/ the WB to be detrimental to the shot. Blazers are only 2" long and the helical w/ 2" worth of vane to work with is very slight. I can understand where your coming from though.

As for the other stuff.... That's all personal preference. If you're comfortable with your setup and you're shooting it well, then you don't need to change anything. Always remember, the guy behind the counter gets paid when you buy something.

Unless they point out specific safety issues w/ your bow, "take it with a grain of salt" like Kanga said.