My 07 commander is a sport. Ive downloaded the build sheet.When I got it the guy told me that its had the front nose replaced a few times due to accidents. The jeep currently has the chrome grille and the bumper cover has the slots for the chrome accent under the bumper. It did not have fog lights. ( It does now, LOL). So. I figured that some body shop must have gotten parts off of a limited and used them. Ive done it. I changed the grille to chrome on my JGC I used to own. But lo and behold, my build sheet lists "Bright grille" as an option. So I have 2 questions. Could you order the chrome grille as an option without the limited package? And, if you get the chrome grille do you automatically get the chrome accent under the bumper? Oh, its also supposed to have "trail rated" badges on the fenders which it does not. Probably left off after paint?
To answer your 2 questions in short order:
1) Yes you could get the Chrome/Bright Grille as an option without having the Limited Trim Package.
2) No, you do not get the Chrome Fascia piece underneath the front bumper automatically, when you have a Chrome/Bright Grille. The Chrome Fascia piece underneath the front bumper is exclusive to the Limited & Overland Trim packages - however you could order it separately and add it yourself if you chose to.
The Chrome Grille was not a "Limited only" option; I have a 2008 Sport and mine came with a chrome grille from the factory but it did not come with the Chrome fascia piece under the front bumper cover. The Sport can come with either a Chrome Grille or a Painted Grille depending on what option was specified when the original owner ordered it. The Chrome Grille would be listed as "Bright Grille" on your build sheet, if it was ordered that way from the factory. You have already stated that's what your build sheet says, so, that question is already answered.
I believe the factory bumper covers for all trim packages come with the slots underneath for the Chrome Fascia Piece, simply for ease of production. If it's a "Limited" or "Overland" trim package, they add the Chrome fascia piece on the assembly line, if it's a Sport they simply leave it "as is".
The External Chrome accents that are typically "Limited and/or Overland only" accents are the Roof Rails with the Chrome finish on the sides, the Chrome Fascia piece under the front bumper cover, the Rear Chrome Grab handles, the Chrome Trim right above the rear license plate on the rear hatch for the rear hatch door handle and the Chrome body-side door moldings.
As far as if your XK should have Trail-Rated Badges - this link explains what equipment/options your Commander is required to have from the factory to be "Trail-Rated" by Jeep:
Also, the Trail Rated badge would be listed on your factory build sheet if your XK came with one from the factory - and FYI, the factory only put Trail Rated badges on the Driver's side front fender on Commanders. Of course that doesn't mean you couldn't order a 2nd Trail Rated Badge and put it on the passenger's side front fender if you wanted it to look uniform - that's what I did.