You are correct - the 4.x version of the RadEditor for MOSS does not override the RichHtml rendering template - only the RichText one.
As for the extra <div> element - it seems to be a MOSS issue. We found that MOSS adds an extra element each time you save the content of a list element using the enhanced rich text column - e.g. if you edit the list item three times, you will have three nested <div> elements. We remove all these elements before the content is saved, but some MOSS code is executed after that and it adds a new <div> wrapper element. Unfortunately, until now we have not found a way to prevent this.
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.