RE: Recommended Arrow weight for ELK
Personally I prefer to be above 450 and closer to 500 grains for elk but what you have there is certainly more than sufficient. The main thing is that it is shooting well for you and you can put it where it needs to go.
I also am not a big fan of serrated broadheads. I would only switch to the premium series rather than the hellfire series of heads.
Don't sweat it one bit. You are ready to go.