To start I drive a 2010 Hyundai Genesis 3.8 and it is craving more power
Welcome to my forum I have read and read and read, so correct me if I'm wrong. If I use a dry system I will have to remap my ECU, add high flow injectors and a fuel pump.
Yes you would have to remap the ECU and POSSIBLY replace your injectors with higher flow versions and possibly (but less likely unless you want a major increase), need to replace your fuel pump. If I use a wet system the extra fuel is added with the nitrous so I won't need to remap, add injectors or a pump.
That would all be correct as long as again you don't want a major increase and don't exceed the surplus capacity of your fuel system. There is usually a 30% surplus capability in a fuel system, so if you are making 300 hp (for example) the pump should be good to deliver an extra 100 hp for the nitrous system. Once you reach that limit you will then have to increase your fuel pump capability but that should be all you need to do. I installed a throttle body spacer that has a port for nitrous but everything I read says to instal the jet 6 or so inches before the throttle body? So can it be ported through the spacer?
If you use a US brand nozzle then it needs to be as far from the engine as possible, because they have a VERY NARROW discharge plume, which requires a greater distance to disperse evenly into the airflow. If you use our UNIQUE Crossfire injector you could locate it in your TB spacer, as the plume is MUCH WIDER and disperses into the airflow in a much shorter distance. For your further information, I 'designed' the Crossfire 'specifically' for that purpose. 
A window switch or TPS switch activates and deactivates the nitrous at specific rpm's
An RPM window switch will do that and our Max Extreme's have BOTH to keep from causing a lean situation at low rpm's
ONLY a correctly designed nitrous system will DO THAT and WON are the ONLY CORRECTLY DESIGNED nitrous systems on the market. The use of braided hose between the solenoids and nozzles and jets located at the nozzle (rather than at the solenoid outlets as WON uniquely do), are the MAIN causes of lean conditions on activation. WON system do NOT suffer any lean condition at any time, because we do NOT use braided hose and our metering jets are located in the optimum location. and if I hit the rev limiter.
Yes it will prevent you hitting the limiter with the nitrous activated and that is beneficial. A purge kit is connected to a button that when activated opens a valve clearing the lines of air and priming the lines for when the kit is activated to the motor (usually right before activation).
Correct but with a CORRECTLY DESIGNED system you do NOT need a purge kit, because it is the use of braided hose between the bottle and the solenoid, that causes a gaseous build up that needs purging before use. WON systems use NYLON pipe whenever possible and this keeps the liquid in liquid form rather than gas, so there is NO need to purge. A blow down kit is connected to the bottle and in a case when the bottle has built to much pressure it vents the built up gas outside of the car.
Correct but with a CORRECTLY DESIGNED system you do NOT need a blow down kit, because it is the use of a rupture disc that puts people at risk of the bottle contents needing to be dumped to atmosphere. WON systems use a UNIQUE SAFE PRESSURE RELIEF VALVE (SPRV) which automatically keeps the pressure in the bottle at a SAFE level so there is no need to dump the entire contents and waste all that money. A warmer will warm the bottle to build an optimal pressure or 900 - 1000 psi. Gauges allow you to read pressure of the bottle. Opener remotely opens the bottle. Once the system is installed you "arm" it and nail the gas pedal. At the predesignated rpm (window switch) the juice sprays and your head is pinned back to the seat. At the top predesignated rpm the juice is cut before the rev limiter. Continue through all gears. Finish line is crossed before the guy next to you. Cheers and applauds rain from the heavens
That is about it but if you chose a US brand kit instead of WON, the chances are that your engine will have grenaded before you made it to the finish line or if you were lucky enough for that not to happen, you'd have to hope that the other guy wasn't using a WON system, as he'd have WOn the race, as our systems produce quicker acceleration than ANY other brand. 
