Moving blog questions about permalinks and html files

I’m new to WordPress, databases and php, but I’ve learnt quite a bit during the last two weeks; Google and forums have saved me countless times. I’ve installed WordPress 2.7 in a separate “wp” folder (www.mysite.com/wp) in order test it and fiddle with it. I’ve been postponing “the move” to my root directory, because I don’t want to screw it up. I already have a standard html web page, and I want to make sure that the switch is as quick and trouble-free as possible.

I’ve read the Moving WordPress Within Your Site, and it seems easy enough. But I still have a couple of questions and I’d rather ask now, than mess everything up and having to fix it afterwards. So, bear with me 🙂

1) Preparation:
Should I remove ALL my old html and image files before I move the WordPress stuff from my test directory to the root directory? (As mentioned above, I have a standard html site there now). I’m just wondering if the root directory has to be 100 % clean …?

2) Images:
If the first steps on Moving WordPress Within Your Site are successful, I assume I still have to change the URL of every image I have in my Pages? (I’ve already made 10 static Pages.) I included the images by specifying the URL, and didn’t upload them via the Media Library. I’ve seen some posts where people are having trouble with images after moving their blog …

3) Permalinks and .htaccess:
I’d like to have some descriptive names for my Pages, like mysite.com/About, mysite.com/MyBooks etc. By enabling permalinks, the page links should be editable. However, according to the admin panel my .htaccess file is not writable (and I don’t think I have access to it), so I guess I have to ask my web host to either make it writable or add the mod_rewrite rules for me (after the move is completed). What is the usual thing to do?

4) html files:
I’ve had an old html site for several years, and I know that many people/sites have linked directly to my sub pages; e.g. mysite.com/About.html, mysite.com/MyBooks.html etc. Even if I enable permalinks on my new WordPress site, I won’t be able to use the .html extension. Is there a way to address this? For example, can I have a few html files (called About.html etc) in my root directory that somehow points to the corresponding WordPress Pages? Will WordPress get confused? Is this a bad idea altogether?

Comments and hints are very welcomed! Thanks in advance! 🙂