You'll be relieved to know that you can reinstall if you wish. The download link has been shared in other threads and even earlier in this particular thread.
The flickering avatar is evidence that the Real Time Editing process is kicking in. It is, of course, possible that someone had hijacked your account and is watching you at work but it also possible that you had the note open in another app.
As well as changing your password you should enable 2 factor authentication.
Do you mean encrypted notes or attached files? The latter is a native function for the file.
Full note encryption is not available and unlikely to come about anytime soon.
There is a well documented support function
https://help.evernote.com/hc/en-us/requests/new
You can also go via X @evernotehelps
The feedback feature recently returned feedback@evernote.com - but this doesn't get a reply. Just a way of suggesting improvements.
The screen shot you provided on 17 August is definitely the classic version of the web interface. If you had the latest version you would be able to display the version number with the release notes and you would have the Home icon at the top of the sidebar which would be in black as per this screen shot from my account... So select Go to new version on the screen you shared from settings and see how that works for you.
As for your original question... Note duplication is, as has said by others, via the three dot menu...
Actually, feedback is available to do via Email to feedback@evernote.com
But remember this isn't a support option. Just a place to submit ideas. So stick with @gazumped's support options.
I think you missed the difference... Evernote is not intended to be a word processor or page layout application. It is a note taking program and there is and never has been pagination provided. If that's what you need then possibly a different program would suit you better.
You are correct that whilst reminders are fully in place they cannot be backdated.
That isn't an entirely unreasonable way of working. A reminder in the past is not a reminder since nothing will trigger in arrears.
I don't think you could plan for reminders in the past ever returning.
To be honest, backing up the local data directories isn't a great approach. The cloud version is the master data so your local data will be overwritten by the cloud.
Better than nothing at all but much better to generate a set of ENEX files which can then be uploaded as needed.
The evernote-backup project will create the ENEX files on a schedule. I understand that Backuppery will do something similar.
I'm not particularly techie but I got evernote-backup working without too much effort.
I've never used Backuppery but those that have report that it can be a longish process with the first pass.
For sure, the recent price increases are part of the problem. Add to that the almost simultaneous major problems with the desktop apps and many folk felt the need to complain.
Without doubt, in general, people will register dissatisfaction rather than contentment.