Hm… it’s not best practice, but that shouldn’t kill it entirely either. Ah I wish you were local, I’d love to take a look at it.

Did you disconnect the battery without shorting the two terminals together or using a metal tool? You should never ever unplug anything in a device until after you’ve unplugged the battery.

No. Opening a device is categorically NOT a warranty voiding action, by law. At least in the US. Though, in this case, it does sound like they damaged the joycon, which would make it not eligible for warranty, but it has nothing to do with opening the device.

I’m from the U.S. most of the services I actually Can use are funded by state taxes. My federal taxes go partially to good things, but when looking at the discretionary budget, which excludes entitlements to which people have directly paid and which the government is obligated to pay out, the vast majority of my federal tax dollars go to oppressing people in foreign countries, and then those weapons are given to police departments to oppress people locally.