A small pair of vernier calipers. I don’t use them a lot, but sometimes they come in very handy.

If that freehub is constructed like the ones I’ve taken apart before, you’re out of luck. Like you suspected, the teeth lock the rotation of the freehub to the hub, unless the screw in the back is taken out first.

You can try hammering in a (slightly larger) torx key or using an easy-out (probably won’t work if it’s very tight).
As a last resort, you could try to drill out the screw (only so far that the freehub comes off, you don’t want to drill into the hub). Then you should hopefully be left with enough left of screw to grab with a pipe wrench.

Unfortunately, this might not be easy to find a solution for. The larger thread size doesn’t seem to be a standard bike pedal thread, so finding a specific adapter is probably not possible.

Another solution might be to use some kind of threaded inserts in the cranks (this would probably require drilling the cranks out for a larger thread). But the standard pedal thread of 9/16-20 is not widely used anywhere else, so finding the inserts (let alone a left-handed ones is probably next to impossible.

Klar hinterlässt das Spuren, aber nichts was man mit etwas Seife oder Spüli nicht wieder weg kriegt. Der Dreck ist ja in dem Moment schon gelöst (sonst wäre er noch am Fahrrad). Nur Festtrocknen würde ich es nicht lassen.

Ich wäre nur vorsichtig dabei, mit höherem Druck direkt an die Lager ran zu gehen. Danach hast du sonst auch Wasser in den Lagern und musst doch alles auseinander bauen und neu fetten.

My router is called Jupiter, everything connected to it is named after a moon. Callisto, Ganymede, Thelxinoe, Kallichore are what I’m currently using.

IIRC, this is actually done at some point in the books.

You can host a Firefox sync server yourself. You could run that on something like a Raspberry Pi in your local network. If you need remote access, use something like cloudflare tunnels (although I guess that’s something else to be paranoid about).

Windows is clearly superior. If you’ve had enough of the settings app, you can just switch to the control center!

Reminds me of this: Falsehoods Programmers Believe About Names