One thing about having a blog hosted at wordpress.com (or on any other 3rd party website, for that matter) is that you shouldn’t have to deal with updates and the likes.
The downside, however, is that you are not able to do anything when things start to suck. I, for example, experience a pretty long waiting to get on this blog (and some others too, that are hosted at wordpress.com). So please be patient with that website if it doesn’t show up in an instant. I can’t do nothing about it, I am sorry.
And no: I am not willing to pay my bucks just to be able to edit the CSS code. To be honest this is something I would expect off a free service already, but then I might be biased. Performance guarantees, that is a different breed altogether. Think about that, wordpress.com!