What if their authority recognizes you?

Unexpected Keyboard
https://github.com/Julow/Unexpected-Keyboard
Available on F-Droid
You can pretty much configure the whole layout. Not sure about gif support though.

Yah, less contagious, but as deadly, which is kinda horrible 😕

Not of it’s neither A nor B ;)
Would you trust ChatGPT to know?

There’s attempts at having payments with 0 fees, that is, if you don’t involve exchanges or payment service providers, who obviously charge a fee for fiat conversion.
Using Nano you have 0 fees for the transaction and ideally as little as 0.25% fee at an exchange for fiat conversion.
It’s not only without fees, it’s very fast (ideallly sub-second confirmation) and eco-friendly (requiring no special hardware, because there is no mining and using very little energy overall).
What’s lacking is places where you can actually pay for things with Nano, but that’s the classic chicken and egg problem.

Fixing issues like energy consumption, confirmation time, fees?
Just in case you haven’t heard of Nano, allow me to tell you it’s an attempt at creating a peer-to-peer digital currency with minimal energy consumption, 0 fees, 0 minimum account balance, very fast confirmation (ideally sub-second, sometimes a bit slower) and 0 supply inflation.
It focuses on doing one thing and doing it well: transferring value efficiently, sustsinably and without middlemen.
It’s around since 2015 and still kicking, getting better and better with each release, ironing kinks out.
It might sound too good to be true, but it’s worth a look; make up your own mind.

And with some small but non-zero chance dying several years later from SSPE.

You aren’t mistaken.
Afaiu it also saves them from https://en.m.wikipedia.org/wiki/Subacute_sclerosing_panencephalitis, which is a delayed death sentence.

Solar panels can have more than 200 watts peak per square meter and provide around 200 kWh per year and square meter, although these values vary a lot depending on where the panels are installed.
Given these numbers, generating 200 TWh annually (which is more than the current electric energy consumption of Bitcoin mining devices) would require 10^9 square meters; that’s slightly more than 31 square kilometers.
Don’t misunderstand this as defending the electric energy consumption of Bitcoin mining! I’d rather see this electric energy being used elsewhere.
I merely wanted to show how much electric energy can be harvested using solar panels.

Yes, there’s a queue called mempool.
Clogging up the network is possible, but costs money (BTC), because transaction fees need to be added to the transactions and those fees need to be higher than those of the highest not yet processed transactions if “regular” users’ transactions shall be delayed.
Miners prefer transactions with higher fees (to be precise: higher fees per occupied block space), because they earn them when creating the block successfully - together with the BTC that get issued when a block gets created.

It’s a bit more than just an estimate. If you want to know more, have a look here: https://bitslog.com/2013/04/17/the-well-deserved-fortune-of-satoshi-nakamoto/
The keys to the addresses exist. Whether someone is in control of them is unclear. It can’t be proven that they’ve been lost.

Just because it’s useless to you doesn’t mean it’s useless in general.

You can look how much space a transaction requires, how much size is available per block and how many blocks per time are being created (at average).
The only way to exceed the figure is by creating transactions with 1 (or few) input(s) and a lot of outputs as they are more efficient in terms of space per tx. Individuals rarely have use for that, but exchanges tend to do that.
If you want to do your own research, start with the fundamentals and investigate the numbers (size per tx depending on type of tx, size per block, blocks per time).

Shall I add the mountain of electronic waste to the list?
I mean, Bitcoin mining devices can literally do nothing else but calculate SHA256.
Once they can no longer be operated economically, they’re garbage.
At least Ethereum’s PoW ran on GPUs, which can be used for, let’s say: gaming!
And Ethereum showed that a transition from PoW to PoS is possible.
I think that Bitcoin sparked a great idea, but way better implementations of that idea are available. Bitcoin has a massive network effect and first mover advantage. technology wise it’s no longer on top of the list.

Prime numbers are searched for doing the PoW. The blockchain essentially contains a data base with prime numbers. As far as I can tell Primecoin never was popular,.but I like the novel approach of doing things, when most cryptocurrencies of that time were lame copies.
Btw. the Primecoin creator made Peercoin, which was afaik the first (and apparently still running) network being secured by Proof-of-Stake.

It’s a lot of energy for a global (!) maximum of around 7 transactions per second.
Unless you want to use the replica of traditional finance called Lightning Network. Then you have more transactions per second and a whole new set of drawbacks.

Not all crypto are the same.
Nano has been designed as digital money.
It has no mining, 0 fees (none for transactions, none for opening accounts), finalizes transactions sub-second (typically), has no built-in throughput limits and works across (political) borders.
I’d say these attributes offer some use and value.

Primecoin wants to have a word having done useful PoW for over a decade.

I stated the reason for it being phased in: prioritizing transactions.

Tell me how to keep a channel open without risking loss of funds through flood and loot attacks.

Nano has alwas has a computational part associated with transactions. It once was used to prioritize transactions. Nano has evolved to a different prioritization scheme. That computational part will be phased out.
The lightning network is a silly attempt to merge bad parts of cryptocurrencies with bad parts of traditional finance: you need the electric energy guzzling Bitcoin and middlemen just like in traditional finance - or would you care to open and close your own channels, pay watchtowers etc. or “simply” use the channels of middlemen?
And how would you have cheap transactions without those middlemen, if operating your own channels requires transactions on layer 1?