there must be basic diagrams out there somewhere.
If you pay a subcontract manufacturer to add 10k units to someone else's production run it saves you $$ and you don't need documentation. That's a common situation for some of the MXQ units that end up on cheap websites. That also assumes the original designer came up with proper docs in the first place, which is also a bad assumption.
The mangled names function in Samba was deprecated aeons ago so it's not the solution. You have two choices:
a) Investigate the "catia" vfs module which can map the illegal : character into something legal
b) Rename files so they don't use the illegal : character
As a general rule the scrapers in Kodi improve over time so if things work in older releases and fail in newer ones it's usually because some bug has been fixed that doesn't allow you to get away with previous shoddy working practices 
Please consider creating an account on thetvdb.com and add missing info/shows instead of creating local nfo files. Then in the future any time you need to re-scrape the info it exists. As is often the case, a little preparation time invested up-front saves effort at some future point.
Not possible because the Amlogic device wtih dual HDMI output doesn't exist. Just use a splitter and set the TV volume to zero so you only hear output from the AVR.
Kodi doesn't support audio input from physical connectors so even if you find a box you won't be able to use those connectors. If you actually mean output then get a Raspberry Pi with some kind of audio 'hat' card, there's loads to choose from.
It is known and updates should correct this in the next couple of days.
Linux (LE) and Android require different options in their kernels. You will not be able to make one kernel and share it between both OS.
I have a dozen addons installed with real debrid and Gaia.
^ You are now barred from all support in this forum
The file in our image is a dummy. We do not (and will not, ever) supply real KEYDB.cfg files. Go look around on Google.
Our current init script does not support this, you'd need to modify it.
Now make a log and identify the specific shows that are incorrectly mixed among the correctly scraped shows; else nobody can be bothered to look through the logfile to guess which one might have something different.
NB: Also conduct an experiment where you rename everything to exactly match thetvdb.com naming and remove all the scene flagging crap. Most of the scraping issues we see are due to lazy users not naming files correctly.
You won't succeed because the compressed .dmg format cannot be directly mounted. You can use dmg2img to convert the image file, but that won't be possible if it's still in active use with macOS. AFAIK the iPhoto's addon was written for Windows/macOS where Kodi has local access to the iPhoto's library structures.
Not possible as there is one system-wide setting. On AML devices there is also a general expectation that everything should be HW decoded as the CPU is a bit low-power for much SW use.
It won't be a CEC issue, but it could be an HDMI/EDID issue from the CEC adaptor (although those things are widely used). Remove the CEC adaptor and connect the TV direct to find out.
The same process works but I would use the opportunity to make a clean install to a new SD card instead of updating the older OE install; make a backup first (or use a clean SD card) and if necessary selectively restore bits like databases, sources and add-on settings.
Raspberry Pi has some advancedsettings tweaks applied by default that reduce the size/resolution of all the artwork in the library. You can apply the same tweak to other devices to mitigate slower scrolling performance in libraries.
Run an Ethernet cable. If you see the same issue it's something weird but probably related to video modes. If the issue is gone the issue was the wireless connection; all complaints about weird playback issues are invalid when using wireless
