I posted this one himeuta and reddit, but you guys might find it useful if you don't visit those places:
Medium finally done. Almost 15 hours later.
I went from total despair here where the boss had 1 HP.
http://imgur.com/ylkY9e2
To total elation here:
http://i.imgur.com/Zs9LUDx.png
I honestly thought this was a wash run - Myoukou dead, I FCFed Ayanami... but it was Bismarck who got the kill with a DA of all things.
My only regret is not doing this on easy. I have no idea if it would have mattered, but the extra medal and ship slot stuff was really not worth my sanity.
I had a lot of luck with surface fleet pre-final dance, but on the final dance I couldn't get to the boss intact so I just gave up and went CTF.
My final fleet: Maya AACI setup with FCF Nagato Mutsu Shoukaku Zuikaku Kaga With FP of 338 (max rank Reppus) - which got AS at all nodes.
Abukuma with torp CI set up Haguro with searchlight Bismarck with DA set up Ayanami Yukikaze Myoukou - all with torp CI set up.
Usually Myoukou is clutch, but she died on my final run and somehow I was able to kill the boss without CI at all... so it IS possible if you're lucky.
For reference, I started this map with around 80k fuel and 75k ammo and ended with 15k each. I would say it actually took around 80k resources because I finished a lot of quests to get more fuel and ammo... so yeah, stock up or just go easy because if RNG doesn't like you, you will waste a lot of resources and time.
I did not sparkle my fleet, but I did sparkle my two support expeditions - 4 ships each so that I could rotate between the two since Boss node support consumes more moral.
I had 0 K kills, but probably around 5 C kills, at least 7 or more X and Y kills and 3 L kills. No idea if any of that matters or not - I did 3 of C, X, Y on purpose and the rest happened because of branching or STF runs.
For people who are losing hope... all I can say is just good luck. Devote a day to it and try to finish it before the buffs run out to save resources , but realistically you'll need two days - one to chip, and one for final dance runs. Sparkling at least an hour, if not more, so take that into account.
I can't think of anything else to say so... god speed anyone trying this map. My the RNG be in your favour.
Also /u/Classiick 's advice to double line (top right) at M node worked perfectly for me for the most part, except for my last run where Mutsu died and I had to FCF her home. But as you see, I was still able to beat it.