Wordpress Category Editor

Please note I'm using a wordress.com blog, not a privately hosted one. I'm beginning to learn that this imposes various limitations and, as a side issue, I'd be grateful if anyone could point me to a definitive list of what CAN'T be done if we're running in that mode. For example, I wasted an hour trying to install a couple of plugins last night, only to (eventually) find someone in an unrelated forum letting it be known that us humble wordpress.com bloggers don't get to see a plugins option.

This question, though, is about the Category Editor and I can't believe that this too is unavailable to those in the cheap seats!

1 - I've mispelt a category. I've added a new correctly spelled version but I see no option to delete the wrong one. I've read references to a "Categories Editor" page where the delete option appears, but I see no option to open a "Categories Editor" page


2 - Following on from that, another reason I need the "Category Editor" is a consequence of using the (impressive) import tool, to drag in my several thousand Stumble comments. However, my Stumble tagging was completely ignored and, instead, every post was allocated to the category "Politics".

I've found a way to filter all such entries and ADD a new category to them (which marks them for my future attention as I begin the long process of proper individual allocation to appropriate categories). What I cannot find is a way to bulk remove the Category "Politics" from the posts. If I could find an answer to my first question, I could, no doubt delete the category "Politics" from the list of categories. It is not clear to me, however, that removing the category would not simultaneously remove the posts.