RE: grains per inch question
Good advice so far, but I'd check out Carbon Tech's website to see if the arrow is spined right for your bow. My experience tells me it is.
Don't get all hyped up about what someone said about the arrow shattering if you hit bone. This can happen with any carbon shaft and even aluminum can break on occasion. Best thing I can tell you is to tune your equipment well, practice diligently, and go hunting. Don't try to shoot too close to the shoulder. Several inches back will do the same job---double lung.
Even with you doing everything right there is always the possibility something will go amiss and you'll hit a bone. It happens. It's not a perfect world out there.
About the only thing that I would be concerned about is penetration. You have low poundage and short draw so make your shots accurate. Use a fairly narrow cut, fixed blade broadhead. Something like a 3 blade, 1 1/8" cut or narrower. This will help with penetration. And don't use an expandable head.