June13 commits bug review

Just reading the code so far:

user_tags.module

function user_tags_page_list() {
  $count = 0; // Overall count of used tags
  $threshold = 1; // How many tags are needed to get displayed
  $font_size = 0.8;
 ...

You seem to be doing something very complicated in this function. Why buil a tag class?
Can not you just be done with nested arrays, output each using theme_user_list($users, $title) where $title is the corresponding relation label?

function user_tags_setting_form_description(){
...

I can see do like to create classes? ;) It is very non-Drupal way to store structured data. Please keep things in arrays or even better -- get rid of the whole function. Keep the descriptions in form definitions. Yes, lines are long but it is not end of the world.

user_tags.install

...
label_enabled Varchar(255) NOT NULL DEFAULT 'Tag me as %a',
label_disabled Varchar(255) NOT NULL DEFAULT 'I am already tagged as %a',
label_user Varchar(255) NOT NULL DEFAULT 'Users who have been tagged as %a',
label_weight int(3) NOT NULL DEFAULT '0',

- I never seen in Drupal database definitions such string declarations, why not keep them in variable_get/set pairs?
- why "label_weight"? should it be just "weight"? Or re-use vocabularys own weight?