Hey Pima, I'm also a first-timer for camaros. Here's some of the things I've gathered from reading these forums.
Mild2Wild switches or Exhaust Commanders for the NPP Dual Mode allows you to switch between a quiet or noisy exhaust. So if you do go the route of ordering a 1LE with NPP exhaust, you can buy this and it's easy to install(all you do is plug it in the fuses, there's a youtube video showing each step). This way, if you don't like your neighbors at 3am you can wake them up or if you do like them you can keep it quiet. This won't void warranty. They run around $80-$90.
Tuners: Tunes will show up on your car's computer and the dealer can see any tunes that have been done. Some claim this won't void warranty, however it will. I wouldn't recommend doing a tune until your warranty is up.
CAIs: CAIs are a simple install and most will add some hp(around 10-15). They come in a range of prices, with the high-end being around $400. These will not void a warranty.
As far as ordering a camaro, it's a great way to customize it how you want. And trust me, there's so many different vendors to use to customize. When ordering mine, I switched my color 30+ times bc I couldn't make up my mind. I liked CRT, VR, IOM, Black...couldn't choose. Finally I stuck with IOM and am pretty glad. The good thing is I'm starting with a clean car that no one has messed with.
The ZL454 package is cool, but you're representing someone else's work and paying a premium price for that. If you like that work, then it's a good deal. Otherwise, there's many people out there that can do custom work for a lot cheaper. This site is great bc the vendors are listed.
I'm not trying to persuade you either way, just giving you a perspective from my opinion. Welcome to the 1LE family