What exactly is hard to navigate? htpcguides.com is the main site and forum.htpcguides.com is the forum. The menus and theme look the same for consistency (and to hopefully avoid confusion). If you have site or forum feedback please post it in the relevant subforum.
There is no approved method, I maintain my installer and Anand maintains his. It's all personal preference which one you want to use or you could use both.
My installer is primarily for servers, it started as a Raspberry Pi only installer and that is why Kodi is included. It only works for the Raspberry Pi.
LAMP - should already be included. The issue with LAMP is scripting mysql and php when they change versions from distro to distro.
Mylar & Headphones - Atomic does have those and so does mine
Plex - is included in my installer for arm and i686 devices
aMule - I don't know what this is, link?
Beets - I don't know what this is, link?
Nzbmegasearch - I had thought about this but it has many issues with starting automatically,
NZBHydra will replace it in due time. When it is out of alpha I will create guides for it and
Jackett - I have thought about this and will just need a reliable method for scraping the latest version from their git. The repo also switched recently so I've been waiting for it to stabilize any restructuring.
Calibre or Ubooqity - Ubooquity is already included in mine, I will consider calibre. I remember installing from source was troublesome.
DuckDNS - I use afraid dns since it's nag free and will probably add that at some point.
Get-iplayer - is this media server or center software?