Not a long term user, I have only had mine for a few months; here are my thoughts.
Very cool!
You seem to have included the Ebay link for both Amazon and Ebay. I believe this is the Amazon link:
https://smile.amazon.com/kwmobile-Case-Kobo-Aura-Reader/dp/B07D3XCM15/
There are also other cases available for that device on Amazon, so lots of options that should work.
Had trouble doing this latest update - download kept failing. Contacted Support who suggested rebooting the device and trying again (duh)... it worked! Having to certify the device with Google Services Framework was a bit fiddly but Monoscribe made it straightforward by providing the GSF ID on the screen where you enable the Google Play Store (in Settings). Click the box to copy the ID and go to the registration page. For this you must remain connected to Wifi. Paste the code into the box indicated, check the "I am not a robot" box and click Register.
It takes a few minutes for this registration to take effect. Of course I kept repeating the registration and was told that the device is already registered... After about 15 minutes, I restarted the device and then was able to complete logging into the Play Store (in Settings) and download my Fav apps - Scribd, Gmail and Calendar. Not the best on this small screen but certainly useable.
I am very pleased with the note taking and sketching abilities of the Origin, although I must say I am not a writer or artist by any means. For me this is a very fun hobby. I have the Staedtler Jumbo stylus and have just ordered the Lamy Al Star stylus which is on sale on Amazon.com for $44 right now (a steal IMO).
Any Wacom EMR stylus for tablets should work (note, not their ones for their very own products except very old ones and current the Wacom ONE).
There are several names for these going around, but there are two generations.
The first generation EMR styluses work, but there's a offset that is usually impossible to fully get with of. There are some good designs among these, but they tend to be worse built and are usually harder to find. Many of these have two side buttons, but usually only one will work on recent devices.
The second generation styluses (some times branded 'Feel' or 'Feel IT') are the ones that work well. Erasers and buttons should work too, although I believe the LAMY button doesn't on the Origin.
For a relatively updated list is Wacom EMR styluses (for tablets, not their professional stuff), see here.