It seems to me that the Tag field needs some modification.
I just ran into some fun with the problems it can cause when html, or even parts of html gets inserted into it.
I think there needs to be a list of characters the user cannot type in this field to prevent it from happening. And for the RSS import, it should skip over these characters, or even go as far as skipping over the stuff between the characters (eg <ThisIsSkipped>).
What are your thoughts?