Actually, if you think about it, the Bookmark Folder way (either in Safari, Firefox, or any other browser) gives you more power over it.
I mean, sometimes, won't you open your browser just to check one little thing, for instance, checking your emails?
In such a case, would you really want all those home pages to load up?
(This is why I myself only have one home page, and that is Google, which loads quickly.)
That's why, IMO, for what you want to accomplish, I find that Bookmark Folders would be the way to go.
And yes, Bookmark Folders.
With multiple home pages, you can only have one "set" of them.
In contrast, you can have many Bookmark Folders,
which basically means you can have more than one "set" of home pages.
This way, you could have a "set" of news pages.
And then another "set" for mail.
Or another "set" for friends' pages.
Etc.
Whenever you want to open one of them, you just middle-click the one you want.
And they would never load when you don't want them to.
Well, that's my suggestion. Hope this is helpful.