I agree, it looks ridiculous, but I kind of like having one of my bikes quiet. I also know that once I change exhaust, I will want / need an ECU flash, throttle bodies, headers, etc, etc, etc. Then I'm right down the rabbit hole again.
1) It doesn't look ridiculous, it looks just fine. At least it does with the bags on... but most of us never take those off, anyway.
2) It is not restrictive with the rest of the system, as designed. Replacing it will not net "any" power. It will just sound different (usually annoying, at least to me), save a few pounds (skip a meal or three), and look different.
3) You will want an ECU flash. It will change the bike in ways you will VERY much notice and appreciate. Do if after you have ridden a while (and pushed the bike hard) and you will appreciate it a lot more.
4) Flashing in no way requires replacing the muffler. Reflashing is the best money you can ever spend on the C14 except maybe necessary ergonomic stuff and the extended warranty.
5) Flashing AND replacing the muffler nets almost nothing over just flashing.
Now, if you want to replace the whole exhaust system (muffler, pipes, header) and TB, THAT is a different story (and it will require a different/custom flash, too). But you don't have to go down that path unless you just like spending lots and lots of money (and it is not a great return on the money). Flash first and see, and you will likely have no interest in that other stuff
So my advice for spending money on the C14 is:
1) Buy the extended warranty immediately.
2) Get it comfortable to ride (seat/bars/height).
3) Add extra brake lights/running lights, larger horns, etc if you feel it is necessary for safety.
4) Learn and appreciate the bike, push it hard. Then reflash it.
5) Farkle it with convenience and more comfort stuff- equipment chargers, trickle charger, extra lights, mounts, coms, grips, screens, deflectors, fall protection (like Canyon Cages), throttle lock, maybe cruise.
6) Cosmetic stuff.