I found them damn helpful, and i got 100% really quickly.
after replaying KS fully twice in a short time, i went searching around for other VN's. One i kept seeing around was Clannad. so, after watching the anime and the afterstory anime, and the movie... I got the VN, and found the english patch.
after getting a couple of different endings, (and realizing that the anime was faithful to the plots, except it merged them all together, and the VN has them all seperate... for the most part) I realized how vast the game really was.
I was completely dismayed that there are no real flowcharts, and just a few simple walkthroughs...
SO, i decided to create a flowchart of clannad.

the main school life is by far the biggest section, and i dont have much done yet.
my afterstory section is functionally complete. Take a look!
Tomoyo After (a sequel/spin-off and a seperate game) is also being worked on.
Anyways, I got the idea to make the diagram from these forums, so even though its not totally related to KS, I thought you guys may be interested.
Link: https://github.com/Morlok8k/Clannad_VN_Flowcharts
technical details: I'm using graphiz dot to make the graphs, which is nice as you just make textfiles, and it automatically places everything. I'm using github as a place to host it, and to potentially work with collaborators if someone wants to help. I'm also used to git for version control with coding, and since a .dot file is essentially code... it was natural for me.