[lindsayw]

My 2 cents-worth: Timeline is the most critical, don't mess with that. I aim at a chapter length of about 6k words for a p-book but only about 3-4k words for an e-book, because most users typically use a font size larger than printed matter so have more page-turns, and page-turns are what subconsciously register as "length". You'll never achieve your "target" chapter length but that really doesn't matter – it's just an ideal, easy chunk of text to read with a logical start and end point. Long chapters tend to be a bit daunting for most users, none of us like to put a book down before we get to a break point.
Changing POV and re-telling a story with a different perspective should usually be part of the same chapter.