Sorry Srhdooba ,
but forget it !
The fire flite express riser will not stand the shock and the vibrations created from newer string materials like 452X or 8125 , it will break ,faster than you think !
A lighter arrow will increase your speed , but the kinetic energy in ft/lbs will stay nearly the same !
You cant make a perpetuum mobile out of this bow .
Take it as it is , or buy another bow .
Btw , your speed isnt bad for this arrow weight and this bow . 2413 shafts have an average weight of around 10.4 grains/inch and a spine of 365 .
Only change that i would make is to go with a smaller outside diameter shaft at the same weight to increase the penetration , for example the Beman Black Max 340 , also 10.4 grain/inch .
Your bow is doing around 53/54 ft/lbs , as long as you dont use mechanical Bh's its fine for most north american game .