The backup function is nothing more than a tar command that archives /storage/.cache /storage/.config and /storage/.kodi so it's fairly simple to use the cron scheduler to execute a weekly (or other frequency) backup, and equally simple to schedule a second command that finds and deletes older backup files.
Enhancing the settings add-on would be better, but there are challenges due to how it's been written and it seems to deter people from volunteering or contributing 
Google translate failed to interpret your statement into a question, can you try again with more words please.
Poking older releases is nice, but you need to test with a current Leia build as that represents the current state of development and where anything can/might/would be fixed. Krypton is a dead codebase.
There were some firmware issues in 8.2.4 so maybe bump to 8.2.5 and cross fingers..
Moonlight is one of our long-term 'problem' add-ons where the codebase appears to continually iterate and things break. So there's no specific reason things are included/omitted, the code has just diverged over time. Someone needs to grasp the opportunity to figure out the issues and submit changes to get things working again. If you raise your right hand and say "I volunteer!" .. half the battle is won 
HDR has a maze of dependencies and some platforms (Amlogic and Rockchip) have fewer of the jigsaw pieces missing (or more hacks to give some kind of HDR output) than others. No platform currently has a complete picture and can claim full support. Kodi v18 is ready for HDR and there is a continuous (slow) drip feed of improvements to AMD/Intel drivers over time. TL/DR; stick with your current video card and watch non-HDR things until support has evolved to a more definitive point.
We make assumptions based on the available facts (of which there are none in your first post). If you start talking about multi-monitor setups we will auto-assume you are not talking about RPi3 which has a single HDMI output.
Regardless of what hardware you have, an extended view (different things on different screens) is not supported by Kodi.
The build-system unpacks sources for a package, then applies diff patches in alphanumeric sequence before building the package. Patches follow a naming convention and need to be in diff format; patches are relative to the root folder of the unpacked sources.
See LibreELEC.tv/packages/linux-driver-addons/dvb/crazycat/patches at master · LibreELEC/LibreELEC.tv · GitHub for examples. If you're working on 'Generic' (4.14 kernel) ignore the amlogic folders which are specific to other kernels (although the format is the same).
Kodi expects the audio hardware configuration to remain static so it will not dynamically switch between two different configs although you could probably detect an HDMI event to run a python script to make changes over the XML API. Also, on most laptop/generic audio chipsets the alsa configuration will just output sound on all devices; and to change that you'd need to dig into the configuration for that specific chipset and come up with a custom audio routing configuration. It's all technically possible but alsa expertise is one of the Linux "dark arts" and you're unlikely to find willing volunteers and a nicely typed-up howto.
Kodi on Windows probably handles this scenario better.
The mobile phone tethered hotspot feature in connman (which is what you're using) is not a replacement for a proper router, and a quick glance on eBay shows things available for £10. Using the right tool for the job is often easier.
Tvheadend runs under Kodi which also runs as root. It's possible to screw up permissions in LE and do lots of other wrong things, but wrong user is never the problem.
Normally ehe onboard WLAN device will be wlan0 and the USB device wlan1, and the connections screen in LE settings identifies the network name and the device which scanned it. So connect to the right network with the right device and the job's done.
You'll need to build the entire distro image as the binaries are in a read-only filesystem. I'm not au-fait with the patches in Milhouse's release but if it has the current work on whitelisting which replaces "adjust refresh" you'll need to whitelist the modes it will switch to, so check that.
Krobar submit a pull request on github with a reasonable explanation for why the config change is needed and it will be considered. As a general rule enabling a couple of minor drivers isn't a big deal and shouldn't be an problem.
If you remove /storage/.kodi you end up with a clean Kodi configuration but not a clean LE install; some config resides outside /storage/.kodi
The first thing to do is test a current Milhouse Leia build because nothing is going to be fixed in Krypton now. If the issue still exists in Leia then it needs to be reported to Kodi devs via their forums.
The version of Krypton hasn't changed since but there will be other changes. It's usually hard to tell with community releases due to all the hacks that get recycled and the dubious version numbering. It's not Leia though, which is the main thing, so apart from the different ARCH (aarch64 vs arm) which requires you to remove/reinstall any binary add-ons the Kodi settings will be compatible.
That location is temporary so don't get too attached to finding things there.
