This plugin removes the mandatory 'Category Base' from your category permalinks (e.g. `/category/my-category/` to `/my-category/`).
Use this plugin if you want to get rid of WordPress' "Category base" completely. The normal behaviour of WordPress is to add '/category' to your category permalinks if you leave "Category base" blank in the Permalink settings. So your category links look like
myblog.com/category/my-category/. With this plugin your category links will look like
myblog.com/my-category/sub-category/ in case of sub categories).
As far as I can tell, no. I have been using this on several blogs for a while and it doesn't break anything.
Simply don't have a page and category with the same slug. Even if they do have the same slug it won't break anything, just the category will get priority (Say if a category and page are both 'xyz' then
myblog.com/xyz/ will give you the category). This can have an useful side-effect. Suppose you have a category 'news', you can add a page 'news' which will show up in the page navigation but will show the 'news' category.
Depends, if its useful enough and I have time for it.