Here is my "Libbitcoin for Core people" writeup, which intends to conceptually summarizes how Libbitcoin works for people familiar with Bitcoin Core.
https://gist.github.com/darosior/97958327835eeef4119418e4d3b6d27f
I intend it to post it to Delving Bitcoin (probably tomorrow) so people can discuss it and you can participate if you're so inclined. I tried to keep it a high-level overview, so i've omitted some details you've shared here. These can be brought up if people ask about a certain area in the comments.
If you have the time to skim through it please let me know if i got anything wrong or feel i'm misrepresenting something.