There is nothing wrong with spray bars pointing straight out. The older systems worked just fine with configuration.
Do not test the nitrous into an engine that is not running. It takes a while to dissipate and that dense oxygen-rich environment you created takes way less ignition source to light off. That will make for a really nice big boom. Only activate the nitrous side while engine is running under load and you'll always be safe. Activating at idle sometimes stalls the intake charge and causes an impressive backfire resulting in damage. Big boom.
If you want to test the plate off the car, follow previous suggestion to secure it or it will try to move unpredictably.
The only reason all the jetting info is confusing is because you are mixing brands of components. That's fine, but now it's hard to know what tune to start with. If your plates came with a jetting chart, stick to the chart to stay on the safe side of things. After it's been tested a few times, then you can start adjusting jetting if you want. At that point, increase the nitrous jet size to lean it out, then you'll get all power available from the fuel you introduced. Just don't get greedy and go excessively lean or cylinder temperature climbs quickly. That's where parts damage starts to occur.