Need help with preloader + heavy site

I am building a Flashsite for a jazzmusician. The site is almost finished and I have three problems:

1
I have a preloader as a separate .fla / .swf file (within “index.html”). When I test the main site through the preloader, what happens is that, when everything is loaded only part of the main site shows (the bottom is missing) as if the preloader has a smaller stage than the main site, and the main site is put within the stage-size of the preloader. I thought the stage-size of the preloader shouldn’t matter?!
Also, the site is not placed in the center at the top, as I want it. It is placed more or less at the center diagonaly and to the left …

2
The musician wants to update some of the content himself, so I have some actionscript that links textfiles (.txt) and a stylesheet/.css to two of the movieclips.
This works fine if I open the main .swf file, but not when I open the site through the preloader-.swf (“index.html”).

3
The musician wants some of his tunes to be listenable, so I have MP3-copressed two tunes from each of the five albums that is on the site (i.e. 10 tunes).
I have compressed the tunes as much as possible without making them sound ugly.
Still the main site is 21 Mb and it takes ages to load, even with broadband!
Is it possible to either make the main .swf smaller without compressing the sound more, or to have the songs (or part of the site?) loading while the viewer is browsing, or have the tunes loading as they are play?
(How come this other site – http://timhagans.com/ – is so quick to load when it even uses both sound and video?)

If anyone is interrested to give this a try, give me a $ quote.

Sincerely
/Truls
http://www.truls.se