Extending the use of tags

Hi xwiki developers! My employer (the University of Oslo, Norway) just asked me to implement the following in xwiki for use in a research project: - When viewing a blog entry, show a list of it's tags along with a link to that tags page. - On a tag page (/xwiki/bin/view/Main/Tags?tag=hotdog), make an input field that will be used for defining that tag, along with the list of the other docs with the same tag. - While editing a blog entry, enable the editing of tags at the same time. So my questions are: 1. I've done the first part writing veolcity code and an xwiki-plugin code. How can I ensure that this list is displayed for all blog entries, new and old? 2. How can I enable the editing of tags along with the editing of the actual text of a blog entry? 3. What kind of persistence (the xwiki db, some other db, xml etc) would be good to use for storing the definition of a tag? 4. It would be nice if I could somehow configure in these changes so I don't have to change so much of the actual xwiki source code and thus make updating to a newer version a lot harder. How can I go about doing this? Any help on this subject would be greatly appreciated! cheers :-) Thomas