This is a problem that the GNU Guix package manager[0] (and presumably its inspiration Nix[1]) are helping to solve. Any two git checkouts of Guix with the same git hash on the same architecture should produce bit-identical builds across time and space for many of the programs it packages. It's not true for everything they package yet, but they're making progress.
This is true, but I think it's an important distinction that store cards are typically opt-in (I haven't come across a store that requires such a card to shop there, except maybe Costco). A facial recognition system would, presumably, be automatic.
They can and do enforce the real name policy. If they suspect your name isn't real (via algorithm or user reports) they will freeze your account until you send them scans of government ID confirming your name. I have a friend with an unusual name, and she's had to go through the process twice thanks to harassers flagging her.
There are a few reports there of games on Unreal Engine 3 having graphical glitches and performance issues under 8.3. It looks like Unreal Engine 3 is not getting updates anymore[0], so it's possible that UE3 users are stuck. (I don't know if Spiderweb use UE3).
As a quick word of caution (which doesn't invalidate anything you've said), Go has a long-standing bug[0] whereby syscall.Setuid doesn't always apply to all threads (on Linux at least) so extra care does have to be taken.
You might be interested in Smallest Federated Wiki[0][1], a software project by Ward Cunningham (creator of the first wiki). It focuses more on collaborative, distributed editing than distributing content though.
(Some might find the documentation for the `guix challenge` command interesting: https://www.gnu.org/software/guix/manual/html_node/Invoking-...)
[0] https://www.gnu.org/software/guix/ [1] https://nixos.org/nix/