Editing Woes!

I've broken down the fanfic o'doom into fourteen approximate chapters. I'm sitting here, staring at chapter one. I realize now that I have no clue where to begin as far as editing goes. Well, that's kind of a lie. I know where to start, especially with chapter one.

Chapter one gets the reader up to speed as far as my divergence from canon, which means it is, unfortunately, long-winded and rambly; not only does it cover where/how I broke free of official events, but it collapses time and space and glosses over the events of approximately five years in two pages.

I have to decide what information is essential to the story and to the reading experience, and that's hard. I'm the sort of reader who wants to know everything. I feel like I'm cheating people when I take out nonessential-but-potentially-interesting stuff. I also know that I need to fix the perspective...with the exception of chapter one, it's third-person limited. Chapter one waffles all over the place, and I definitely don't want that. On the other hand, it's going to be incredibly tough to transform it all from total omniscience...

What's the rules? Would it be too disrupting to go from omniscience to limited, if the perspective changes over at the beginning of chapter two?

*sigh* Maybe I should just stick to spell-checking until I get my opinionaries reading.