This would be cool – the problem, 99.999% (source: I made it up) of people just know to open the camera app to scan a QR code. So if this is displayed publicly, nobody would know how to scan it without going to another website anyway, which I feel defeats the purpose. Very interesting implementation though!
M1 with Asahi is a very bad idea, unless you want to be wrestling your computer to barely work. Either get a Framework laptop, or one of the new Asus Zenbook S 16 laptops (I just got one, and it's really nice. Works on Arch Linux with some kernel patches, which can be gotten pretty easily via the linux-mainline-um5606 AUR package).
Touch screen support depends on your desktop environment, I'd recommend giving a modern GNOME + Wayland setup a try. As for battery life...yeah, that's hit or miss. There's some management tools that can help sometimes.
That's really weird, I also have a Gullikit controller (the one with the hall effect sticks) and it works perfect OOTB on my desktop & laptop, both running Linux. Maybe try switching the mode on the controller to Windows/Android instead of Nintendo Switch?
Idk, I think most beginner distros are fine. If my dad (who primarily uses Apple products, browses the web, checks email, that's it) can figure out Fedora + GNOME, I think anyone can.
There's so much saturation in the SaaS/"indie hacker" space, basically anything that could be done is already done. The nicher you get, the easier it is to either implement yourself or build an actual consumer app around.