PinkElephant

Depends on the client you are using.
If it is a desktop client, type the search term into the search field. Click in the note you want in the search list, selecting it.
Now simply click on the "x" in the search field, deleting the term. This will remove all highlighting. The selected note stays selected, but without highlighter.
If you want to search again, you don't need to type it all. The 3 last search terms are stored in the search function. Just click into the search field, and select them from the dropdown list.

This is a known and still not resolved bug. It seems it cuts it down the web clips to the width of a mobile screen in portrait mode.
The only way around it is currently to simplify the clip, by clicking on it and then selecting the magic wand.
This will convert the clip into something like reader mode in a browser. All content, but a simple format. Hint: Once converted it can’t be converted back again.
To make EN aware there is still a fix pending you could issue a support ticket.

No, not yet.
More calendars are in the making, the next one is expected to be Outlook.
A workaround is to create a Google calendar, sync it to whatever you use (like iCalendar) and connect it to EN.

The forum is user2user. Use the feedback function build into the client to send your request to EN.

Probably it was encrypted using an older version of EN. The new version is very sensitive against any formatting of encrypted text: No bold, italic, underline, no colors, no numbered list, bullet points etc.
Use a legacy client to decrypt the text and remove all formatting. Encrypt it again. It should work then on v10 as well.
https://help.evernote.com/hc/en-us/articles/360052560314-Install-an-older-version-of-Evernote

This is usually related to a missing authorization in the Macs settings, Security & Privacy.
Go check if EN is listed in the apps allowed to do screen recordings. If not, it probably needs to be added there.

The web client counts as a device. 1-2- over …
https://help.evernote.com/hc/en-us/articles/218558068-Understanding-the-device-limit If you can buy an iPad and a MacBook Pro, and now have nothing to spare for a subscription, you may have invested too much into metal, and not enough into making it work intelligently …

This has been reported before. You could try this:
Go to File > Sign Out [name] from the menu bar. Select the "Remove my Evernote data from this device" option, then click Sign out. Restart your computer. Sign back in to Evernote

To fix a problem with corrupted local data, you can follow this recipe:
Go to the Evernote menu, Preferences, and uncheck „Keep data when leaving“ Log out of EN (File menu), quit EN (cmd-q) If you want to be very sure, restart the Mac Open EN, log back in, wait for it to run an initial sync. 

You don’t print. You use the Macs printing process to create a pdf.
You choose Print Note, the Print dialogue box opens. At the bottom in the middle is a small „PDF“ button. Click it, a submenu opens and allows to specify where to send the pdf. The “print“ will never see a paper, it goes as a pdf right where you send it.
This ability is build into MacOS. EN does not need to spend dev hours on something the Mac can do anyhow. I prefer they use the devs for unique features.
For example to fix the treatment of tables in their own pdf export.

If you launched a browser first before you launched EN inside of it, it is the web client.
If you launch EN directly from an icon without first launching a browser, it is the installed version.
Your screenshot shows the installed version - the web client has no keyboard shortcuts. 
The auto filing option FOR THE WEB CLIPPER(!) is in the settings of the web clipper, not in any of the clients. You can enable or disable auto filing there. If it is active, EN will try to guess into which notebook it will send the clipped content. This overrides the default notebook.

You can upgrade, but you can’t downgrade back to Plus afterwards. You can only stay on at least Personal, or fall back to Free.

No such option, AFAIK not even in legacy (that in general has more printing options).
You can only copy the content elsewhere without the title, and export / print from that app.

And I am just another user, so sorry, won't connect.
My Mac is a high specced 2019 Intel MacBook Pro, BigSur 15.6.1, EN 10.25.
But there is one difference I see - which is I run the direct install from Evernote.com, not from the AppStore.
The AppStore version is exactly the same code - but coming from the AppStore, it runs restricted, in a sandbox mode. This means it is limited by MacOS in the way it is allowed to interact with other apps - which is what we see here.
If you are not tired of trying, I would completely remove the AppStore version from the Mac. I am not aware of AppDelete - with AppCleaner you need to be careful to really remove everything, program and data. It sometimes leave out some data files , which need to be selected manually.
Then restart the Mac, and get the download from evernote.com. Install from the DMG, and give it another try.
Thumbs pressed !

This is probably the most comprehensive document:
https://help.evernote.com/hc/en-us/articles/208313828

You could try this: Go to the Evernote menu, Preferences, and uncheck „Keep data when leaving“ Log out of EN (File menu), quit EN (cmd-q) If you want to be very sure, restart the Mac Open EN, log back in, wait for it to run an initial sync. It will rebuild the local database with a copy of the server data.

Most likely something went wrong with the download, so it duplicated the notebook, and started another download.
Probably you need to get rid of the corrupted local copies (all of them) by deactivating the offline option for these notebooks. After the unsync is confirmed, close the app, delete the apps cache and switch the phone completely off. Wait a little, back on, open EN and wait for all (possible) activity to terminate. Then switch the notebook back to offline use.
I am not sure it will help, but I think it is worth trying.

Quite simple:
Go to your account, personal settings.
Disable the “Automatic filing” option, right below the languages selection.
This will stop the AI guessing and send all mails into your default notebook.

You may try this
Go to File > Sign Out [name] from the menu bar. Select the "Remove my Evernote data from this device" option, then click Sign out. Restart your computer. Sign back in to Evernote If it does not solve the problem, ask support.

No idea.
Standard procedure „cure for all ills“ for the Windows client would be this:
Go to File > Sign Out [name] from the menu bar. Select the "Remove my Evernote data from this device" option, then click Sign out. Restart your computer. Sign back in to Evernote If this doesn’t help, issue a support ticket.

There is no setting where to open.
Usually EN desktop / web will open the last view before closed.
If it is the web, I would try to clean the EN cache in the browser, and see if it returns.

There is note history running on your account, independent from your subscription status. It is a versioning tool, conserving older versions of every note. It does so even for Free accounts.
However access is a subscribers feature. If you are on a subscription (at least Premium), you can recover older content even if it was erased by later changes. You need to use a desktop client or the web to do so.
Here is more about your options to recover missing content:
https://help.evernote.com/hc/en-us/articles/360001858027

Depends on the setup.
Personally I have stopped using the direct scan to EN from my ix500 altogether. The scanner creates a guess of a file title, that will become the notes title after sending it to EN. Both are usually *****, and changing them is double work.
My current workflow is to scan to a folder using the ScanSnap Manager software. The file is OCRed, and then I name it. The save dialogue is set up to save into the EN import folder. The file is send there, it is imported within a few seconds, and attached to a new note.
The import folder is a new feature of v10, at least on the Mac.

It is a known bug, reported, acknowledged, no date for a fix known.
Just check the release notes when an update shows. I think they will mention it there - AFAIK only relevant for the Mac client.

OK, desktop challenge. This is on my MacBook Pro, BigSur 11.6, Safari browser ver. 15.
Works, and by seeing the blue + sign it is even easier to follow what is going on. The + shows by itself when moving the mouse pointer over it.
My conclusion: I don't know what technology EN uses to build the animated web client. But maybe something on your Linux desktop or in Chrome (maybe a popup blocker, or similar) is blocking it. So it seems to me this is more an issue for support than for the forum (which is user2user).
 

Tables WebClient.mp4