Correct time is a good thing but is also cosmetic to the Kodi GUI so there is no reason to make Kodi start depend upon it. From a support perspective this would make things worse given that some routers act as bad/misconfigured NTP servers, users have a habit of adding typos to their input, and some ISP's blocking port 123 (lord knows why, but it happens).
As 99% of NTP issues are seen on Raspberry Pi .. the cure is adding an RTC card not adding workarounds to the OS.
You can't downgrade the drivers but you can try upgrading to a current Milhouse build as these are running a 4.8 kernel which resolves some Intel GPU issues; although no guarantee this is one of them.
It should work as the Heroku cloud service talks directly to the Kodi webserver so there's nothing to install on LE, but doing this requires you to expose the webserver on your Kodi box directly to the Internet which is not a great idea. It's not really designed/intended to be exposed that way and it's only password secured 
v7.90.007 will appear a few days after Kodi release v17b3 .. which is maybe due in the next week (but no guarantees; moving targets etc.)
It's probably possible, but you cannot use pip to install things in LE so the required files/config need to be packaged up into an add-on.
btw, anything involving Amlogic hardware should be labelled with "Here be dragons" due to the higher level of boot/run complexity vs. normal x86 kit which is comparatively straightforward.
It shows a TLS handshake time-out, so maybe NordVPN have a network issue or you're using a config that talks to incorrect servers - but ultimately that's a guess as I have no clue about that add-on. I suggest you contact the add-on creator for help; it's not one of ours.
No debug logs. No problem
Yes in theory you can take the patches and various kernel bits but there is no nicely written wiki article to explain the entire process so in reality it's one of those "If you have to ask how it's done, you're not going to succeed at the task" cases. I don't mean to be arrogant in saying that, it's just that I have a load of experience with people trying to fiddle with the logical and well structured LE build-system, and that's how it plays out.
In some devices the region coding is embedded in device firmware so selection is handled automatically by the kernel. In other devices the default is a world region code. This is in theory what RPi3 has, only the wireless driver has some caveats on auto-detection and only sees channels 1-11 unless you force the region code (which has nothing to do with Kodi). We don't ask for the region code because a) we have no way of asking it currently, b) no other driver needs this, c) out of tens of thousands of installed systems only about 10 people have complained.
No it would not. Setting the region in Kodi has nothing to do with wireless region in the OS layer.
There are no PDFs but
The drive will auto-mount under /var/media .. as long as there is no issue mounting. If it never appears in Kodi log-in over SSH and run "dmesg | paste" and share the URL generated here so we can see the kernel log which will have clues on the reason it doesn't mount.
There's no attachment. If you can't share here post it to imgur.com.
Use "ethtool" to check the port speeds. It can also force the port to a higher speed (instead of auto-detecting) although it's unusual for auto-detect to not get things right. Do the usual things like trying a different Ethernet cable too..
Aside from testing the current Alpha (or Milhouse) builds which will have newer drivers, the best thing to do is capture a couple of mins of the offending channel to a file that can be shared (along with a debug log) with Kodi developers.
LibreELEC.tv/linux.aarch64.conf at master · LibreELEC/LibreELEC.tv · GitHub
support for the kernel module is compiled in. If it needs more than that, someone will need to tell us what.
Please take a photo of the stack trace on screen; close up and steady enough that we (or someone who understands it) can see all the text clearly.
