GPU: NVIDIA + Intel
Just wondering... Do you really need the Nvidia GPU? The Ivy Bridge GPU of the C1037 is quite capable on its own, upto decoding 4K h264 actually. I haven't tested my C1037UN-EU box with the very latest LE builds, but it has had no graphics issues yet.
The simplest and fastest way to start a fresh video library is to delete the actual database (file) via SSH.
Browse for the userdata/Database folder when you are not using a MySQL shared database, delete the MyVideo104.db file (or v105, whatever is the latest). After that, reboot LibreELEC.
The Settings Addon can only hold a limited amount of different settings. We simply cannot put every single setting for all supported hardware.
A specific, and separate addon for e.g. Raspberry Pi would be an option. PR's for such addons are welcome.
I know that hdmi_rotate works on my 2nd monitor, but I never had to use lcd_rotate. You sure you have "lcd_rotate=2" in the config.txt, instead of "lcd-rotate=2" ?
LibreELEC works with 2 seperate partitions, the system and the (data) storage partition. What do you need the /boot folder for? Your config.txt file is sitting in the /flash folder, which you need to change to "rw" if you make any edits/changes.
Thanks for reporting. It's a known bug, and perhaps not at the very top of our priority list, but it will be fixed. 
Don't start lame clickbait topics for a topic which is apparently not finished yet: "(to be continued...)".
Use the File Manager, and follow the "/var/media/My Book" path. Your WD drive should show its contents there.
If you want to add videos from that drive, use that same path.
When browsing through the folders, check this location:
/var/media/My Book
Linux can be pretty picky about drives that are not unmounted properly.
If you can use SSH, connect your WD drive, log in via ssh (root/libreelec), and give us the URL for the following commands:
dmesg | pastebinitblkid | pastebinitmount | pastebinitIn case of doubt, always provide debug enabled log files:
HOW TO:Provide Logfile - LibreELEC
I hope it's not for any usage on a Raspberry Pi device. LE on the RPis does not use x11.
All LE builds run in a plain vanilla Linux environment, plus only the necessary bells & whistles to run Kodi.
I'm not that familiar with Android hardware specifics. SPMC is a specific Android build for Kodi, but i guess that not every program can support all hardware 
LE for Android, that is not going to happen.
Look for SPMC in the Play Store instead.
The Backup function only covers the most important folders in the storage (data) partition. The other folders will be auto-created by Kodi if necessary.
The root folder will not be shown as the LibreELEC system is stored on a read-only system partition. Those files will not be backupped by the Backup/Restore function. If you want a full disk image, I suggest using tools like CloneZilla.
At the moment there are no people in the LE team with the time (and perhaps also skill set) to create a separate and specialized config addon for setting up connections via OpenVPN. Should someone be willing to step up and create such an addon, we are more than happy to review their PRs.
Without such an addon, it would be pointless creating our own documentation when there is already a very detailed manual on the website URL you have been given.
Please don't crosspost.
Topics can be moved to a different located when asked nicely.
Have you checked the .srt file for any color coding?
We tried to do a "Wingardium Leviosar" spell, but details of your computer are still not fully clear.
So please upload a kodi.log file, and inform us of any other hardware that might by in your PC.