Arduino VS meta-raspberrypi

I learned from looking at example code in the Arduino IDE (a really good and free code editor https://www.arduino.cc/en/software). The Arduino IDE allows you to add more boards (like ESP32, ESP8266, Tiny etc.) so you're not limited to using only their Arduino boards.

Based on what I am seeing from the Keystudio website, the software you need is just the Arduino IDE. This can be downloaded from Arduino.cc for most operating systems, including Mac OSX. You may need to install support for other boards or install libraries to make it work with the Arduino and hat included with the kit.

Download and install the Arduino IDE. After installation, open the IDE to the first sketch.

Well, your first course of action would be to download the software - https://www.arduino.cc/en/software

You can download the IDE from here.

You will need to download and install the Arduino IDE to do that. I would suggest the Legacy 1.8.x IDE or the Arduino Web Editor (which will still require that you install some software on your computer to help transfer the program to the Arduino).

The software used for that video is the arduino IDE https://www.arduino.cc/en/software

Wiring: You're on the right track with your wiring assumptions. The red wire should connect to the 5V pin, the black wire to the GND pin, and the green wire to one of the analog input pins (A0-A5) on the Arduino Leonardo. For example, you can connect the green wire to the A0 pin. Programming the Arduino Leonardo: To translate the handbrake input to Assetto Corsa, you'll need to program the Arduino Leonardo to act as a USB HID (Human Interface Device). This will allow your computer to recognize it as a game controller. First, you'll need to install the Arduino IDE (Integrated Development Environment) on your computer. You can download it from the official website: https://www.arduino.cc/en/software

How do you figure Pis have bad integration with Yocto?

https://github.com/agherzan/meta-raspberrypi

For what it's worth, the entire Pi lineup is also well supported by Buildroot. In-tree, no less.

Embedded linux exactly. Major OEMs are using yocto. Check https://www.yoctoproject.org/

Been there. You don't want alpine or debian. Good gpos, but what you want is Yocto, which will let you build exactly and only what you need piece by piece including only the kernel modules for your hardware, the exact applications you use and no extras, and with a little extra tweaking, you can wire in Mender for ota updates and the ability to push custom images to clients that need specialization, or even fully unlocked images for customers that need it, plus if you're using an SD card, you can send users recovery drives instead of shipping full devices or let them build their own images without your proprietary code

I second Yocto. It's the kernel in use by the OpenBMC project

One last "option" is yocto but tis is not good for desktop, but it can be a fun project.