Great to see another Nitrous user come along. That's I'm glad to see that you have done your home work and know your data.
I think the bottle should have been placed differently but to each his own. Just know that when your bottle gets lower in pressure, you might not be getting all of the bottle because of its position.
If you open up that bottle, its just like a fire extinguisher. It has a hose which extents near the bottom of the tank. During hard acceleration when bottle pressure is low (even with a bottle heater) all of the nitrous will be stuck at the middle of the tank due to your position.
If you had the bottle placed where the bottom of the tank is facing the rear of the vehicle and the top end of the bottle facing inside the cab. Then when you accelerate all of the pressure goes to the bottom of the bottle where it gets picked up by the hose inside and into your feed line.
There is a reason why those brackets are placed the way they are (one higher than the other) its due to that specific reason.
I don't see any finished pictures of the engine bay other than when it was under contruction. Where did you tap? Are you running a single fogger system? Also, the placement of your bottle will not let you be able to use that thing at a track. If you are running at the track and get tech'ed properly. Track rules are if your bottle is inside the cab, your gonna need a safety blow down tube that vents outside the vehicle. Also, I hope you don't have your bottle with you alot during the day as that bottle will blow its rupture disk and vent all of the nitrous inside the cab. In its current position. You won't be able to have a blow down tube installed. If you do it will have to be a long one and your gonna have to drill through your floor.
Congrats.. Now step to a 100 shot like me