Frank i hope you can help me

I want to race in stock not drift, the hobbie shop told me that i need the s
because it had the upgrades already and the diff is stronger.

my questions are these as i am very new to racing:

1-i got the manual from cyclone tc and have set the diffs up the same (i put a pro spec in the rear and normal fixed in the front) is this right

2-it came with a plastice 18 t pulley and a one way pulley but when i set it up how the book says it doesnt pull the belt becasue it is going the wrong way, so i turned them around and have the plastic running the rear and the one way running the front which means when i brake it is like pulling up the handbrake

3-i am currently running a 40 pinnion with a 96 spur, but i want to go to stock brushless what, i got told to run the 7.5 not a 13.5 is this good

4- as i said i am very new, what do i need to convert the s to a touring monster, do i need to get a new pulley shaft?