Moving from Entourage to Mail

I'm playing with moving from Entourage 2008 to Mail to see if I can live with the latter. A few questions:

1) how can I import my account information? Not messages--that's done but still an issue (below)--but my email account information (address, login, password, server info, etc.). I have fifteen different email accounts and dread the idea of adding them one at a time.

2) After importing messages from Entourage, I have a bunch of folders under "On My Mac," based on how they were divided up in Entourage. Is there any way to move these to my Inbox under "Mailboxes"? It seems strange and disordered to have my messages scattered about like that in different places (since new messages will appear in my Inbox). Moving them is excruciatingly slow: if I drag the messages over, the Mail Activity pane says it's Sending mail, and moves at a few kps. Moving the thousands of messages would a LONG time, as if I were actually downloading them from the server.

3) having imported messages from my .mac account, many of those same messages have now reappeared on the Mail page of my MobileMe account--scores of them, many years old. What's going on? They weren't there before. And when Entourage checks my .mac account, they get downloaded again.

4) the whole lack of a Show/Hide read messages command irks me--such a basic and simple command to have (and Apple apparently recognizes the need for it, because there's a slow, clumsy workaround in Mail's Help). Am I missing the point with how Smart Folders work? I have multiple folders that incoming mail gets sorted into, e.g.,:

Inbox

Newsletters from ABC

Newsletters from DEF

Website email

Business email

and so on. To use Smart Folders for this, would I then have to create,

Am I missing the point with Smart Folders? I have multiple folders that incoming mail gets sorted into, e.g.,:

Inbox read

Inbox unread

Newsletters from ABC read

Newsletters from ABC unread

Newsletters from DEF read

Newsletters from DEF unread

Website email read

Website email unread

Business email read

Business email unread

I have a number of such sorting folders, so this starts looking really cluttered. Or, again, am I missing something? I'd still prefer to simply be able to toggle the view for Show Read only and Show Unread only.

5) Is there any workaround to check different email accounts according to different schedules?