WYSIWYG alternatives

Hey!
I was wondering to get your input on this, didn’t know whether to post this is SS or CS since it has to do with both, but what the hell I posted here. Anyway, I’m planning to make a CMS, mainly for my own use but I’m planning on making it GPL or something and sharing it, people might find it useful.

The thing about it will be that it serves a designer who wants to offer their clients dynamic sites. Now of course there are dozens of CMS’s, but lots of them are very complicated for the end user to use and require you to tailor your site design to them, not the other way around. I’m looking at something where a designer can code his site in (X)HTML/CSS from scratch and then to offer an API so that he can sorround parts of his markup with functions to link it with the cms. So the main focus points will be
[LIST]
[]Build a site from scratch, worry about linking it with the cms later
[
]Very easy to use for the end user, no bloat or stuff that they won’t use
[*]Very hard for the end user to make the site ugly with their inputs.
[/LIST]
Now the last point is what I’m worried about. Everyone knows what happens when you hook up a client with a WYSIWYG editor for their site. They go all edit crazy, change fonts, add five line breaks between every line and generally make it look like hell.

How would you guys go about solving that problem? Know of any CMS systems that have solved this nicely? I don’t mean like code, just the general plan. I was thinking of setting up each block of text as an entry in a database. As a module, if you will. And it’s linked to the page that’'s being viewed via a FK. So if I then enable on a page so that the client can add more blocks and not just to edit the preset ones, it can be like a news page. Or I’d just make it a special news module and not just the generic ‘block of text’ module.
How’d you go about solving that? Giving the client all the power to edit content but to give them very little in the way of editing presentation.

Also, sorry for the long winded post, I can post a picture of a baby pony or something later to make up for it.