Stalker has some nice Bows, glad to see someone else trying traditional bows.
You are right at 10.5 grains per pound with your current arrow setup. Typical arrow weight range is from 8 to 11gpp so your on the top end. (most) bow manufacturers allow as low as 8 grains per pound without voiding any warranty (check yours) with that said, if you wanted some more speed you could drop down in total arrow weight say around 450grns you should see a marked improvement in speed and arrow cast.
Stick with it, its a whole new experience shooting a stickbow.