You can try to leave out some of the scenes that you haven't written yet. Its quite a long story already. Besides, you have all the important parts of the fic written already. Most of those unwritten scenes seem redundant to me. I leave it to you to figure out which ones to drop.
As to Keiichi's air-time. It doesn't really matter, this isn't his story anyway. 

1: I have reference to two musical peices,  the second is Skuld puting a tape >in her walkman.  

Assuming its the one before she goes to whack Urd, "Flight of the Valkyries" would be a good choice