I'll be the first one to agree that I don't have a clue regarding the large scale view of things. As you correctly pointed out there are a lot of different users each with his own workflow and a lot of technical details. Thanks for pointing this out.
The zip download (available also on Github, and being developed for official Kicad page) will cover basic users. Yes a tool for setting fp-lib-table and symbols table would be really welcome. Is the fp-lib-table equivalent for eeschema coming with V5? If so, then fp-lib-table and symbols-table could be included in the repo and .zip file, which would result in quite clear instructions how to update the tables (copy them)
A user will download zip file multiple times, while with git only initial clone takes some time, from then it should be quite quick if you do it regularly
As for the installation of git, I personally don't see it as a turn off. If you need advanced features in Kicad you need external tools (Freecad, ...)
Also my view on git (not git in particular but on SCM tools) is that if you program even a little bit, this is a basic tool that you have to have at your disposal. Just like a blacksmith needs an anvil, only hammer and fire are just not enough. From my experience a lot of people designing circuits have some programming experience and would benefit from git. But before you point it out I agree that Kicad is not in the business of educating about SCM tools. I am just saying that if Kicad requires Git for advanced library management I don't see this as a problem.