I see what you mean, so let me try to explain:
You don’t have an ID for the account (like a username, random number or even public key) but instead an address for your chat with someone (this is the queue where your chatpartner sends their messages to). So every address is unique only per chat, no unique ID per account or so.
If you still have questions about the SimpleX system, feel free to ask and I will give you useful links.
SimpleX isn’t able to share your profile-data between devices. Instead you connect with e.g. the desktop app to the phone to use the phone-profile, but it need to stay online, which can be inconvenient.
With the CLI version you are able to run it on some (private) server and then connect the phone and desktop app to it. But it is still not really convenient, as you need to establish a tunnel (for example SSH port forwarding) to the server (the clients don’t support connecting via internet URL the last time I checked).
As far as I know you still need a phone number to create an account. But for connecting you can use the new usernames (and make sure to disable automatic number sharing with contacts in the settings).
SimpleX doesn’t need a phone.
The desktop app can run standalone or linked to the phone-profile (but the phone must stay connected for that).
They also have a CLI version (which you can use as a central hub for your profile).
But as you mention, NaN propagates.
So at checkout, your wallet will become NaN, as the shops money balance. Then it will spread to your bank account and before you realize what happens the whole banking-district is in flames.
I’m in the “c-h-own” team.
Have you tried to enable only one codec and set the default quality to something like 720p in the preferences?
Which instance are you on. I use piped.adminforge.de with uBlock and it works fine. Also the feed shows stuff from my subscriptions (I think I adjusted something in the settings for that).
As far as I know the SimpleX team adds their servers to the preconfigured list of servers in the app.
So if you host SMP servers for others, you could share their QR code (along with a quick description) in some forum or your own website (I know a hoster of serval private services who also maintains SMP nodes).
For info about hosting such a server, see here.