Is Klipper worth the hassle on an old Ender 3 V2 or should I just stick with Marlin?

You won't brick the printer doing this, I promise. Flashing firmware on an Ender 3 V2 is just putting a file on an SD card, sticking it in the printer, and turning it on. The board reads it and installs it. If something goes sideways, you just pop the card back in and reflash the stock firmware, which Creality still hosts on thier site. The only real way to kill a board is shorting something out while it's powered, and that risk exists wether you ever touch firmware or not.

One clarification though, because the online videos blur it: the Pi doesn't replace the printer's firmware, it runs alongside it. The Pi takes over the thinking (motion planning, which is why it's smoother and quieter) and the printer board just executes moves. So you flash a firmware like Marlin or Klipper onto the printer first, then connect the Pi to the board with a USB cable. If the Pi ever dies, the printer still works standalone. I ran mine off a Pi Zero 2 W for a year before upgrading, and being able to send prints from the couch and watch the camera is what got me hooked.

If the SD card flashing feels like too much for a first step, there are boards that let you flash over USB, but honestly the card method is fine. Watch one walkthrough video for your exact board, because the V2 shipped with a couple of diferent mainboards over the years and the filenames differ.

On the direct drive bracket: I used a cheap printed bracket with the stock extruder for months and it printed PLA fine. The catch is that the stock extruder is heavy to hang off the carriage like that, so you'll get more wobble and ghosting on tall or fast prints, and you'll be retightening the bracket now and then. For functional brackets and organizers it's honestly fine. The full direct drive units are lighter and better if you ever want flexible filament, but for plain PLA you don't need one yet. If you do the bracket route, print it in PETG or ABS, because a PLA bracket right above a warm hotend will creep over time.

Been down this road a few years back with my original Ender 3, and the stock mainboard served me fine without any of that untill the day I wanted prints while away from the machine. That's the real reason for the Pi setup, convenience and remote monitoring, not print quality. If the machine is making good parts sitting on a desk next to you, there's no shame in running it bare bones. I left mine stock for over a year and churned out brackets and drawer organizers the whole time.

On the bracket route, agreed it works for PLA. One thing from experiance: the cheap brackets flex, so keep print speeds sane and you'll never notice the difference. Nobody needed a fancy setup back in 2018 and half of us were printing fine.

Second the bracket route, I ran one for like a year before I finally bothered with a proper direct drive. Worked fine for PLA organizers and stuff. Mine did loosen up over time so I got in the habit of checking it before long prints. If you're handy with a 3D printer you can just print a better designed bracket with beefier screws than the cheap Amazon ones come with, costs you basially nothing. Also if you do go the Pi route eventually, you don't need a fancy one, an old laptop with the same software works too if you've got one lying around.

This thread is making me less scared to try the Pi thing on mine. Question about the camera part though, does the little Pi have enought juice to run the camera and the print stuff at the same time, or do you need the bigger one? I've got an old phone webcam lying around and wondering if that even plugs in the same way or if it has to be a proper camera for the Pi.

Quick update — I've been thinking about the Pi setup since the replies said it's mainly for remote access. I tried hooking up an old phone webcam to my test Pi. It surprisingly recognized the device imediately, which makes the remote monitoring idea much less daunting.