Another Chapter Down

I have completed another chapter in my novel and a lot of interesting questions have come up. When I first took up pen and paper to attempt to write a novel, I began with chapter lengths of about 5 pages. This last chapter I wrote has in excess of 20 pages. Do all chapters need to be the approximately the same length? My wife like to have short chapters so she can read an entire chapter before going to bed. When I read a book, I don't worry about how long a chapter is because I will lay the book aside and continue where I left off.

Another interesting question is about rewrites on a manuscript. My wife was looking at the acknowledgement page of the book she is reading (not my work, the work of a published author) and it made reference to someone that encouraged the author even through the sixth rewrite. Isn't this a little excessive, or was the novel just bad from the start and required that much touchup before it could be published?

As I write, I make changes to the story line, characters, etc. Does this constitute a rewrite or must you wait until the entire novel is written before you do any rewrites on it?

I will continue to push forward with this project and keep my friends posted on my progress. Maybe I will have some answers before I am finished.