I've been thinking a bit more about this and it will have to be at leaste five new fields for this. If an image is to be added another field has to be added as well. But I could do it though.
But if font colors should be updateable as well I think it would be best if the information for the instant markup boxes are in a separate table. It doesn't have to be, but I don't really like the idea to have rows in the Markup table that are not Markups...
I haven't looked at how post icons work since I don't use them myself, but I guess it would be quite easy to add new ones so I'll look into that.
Changing images is just a matter of uploading them into the images directory, is a admin script for that really needed? It wouldn't be that hard to do, but it seems a bit overkill to me. =]