Does it matter where my academic website is hosted, for issues of intellectual property?
I can hardly see how writing your own comments on someone else's published work can come close to any sort of copyright infringement. Obviously, you would not re-publish someone else's papers in your blog? Small quotes are allowed in the UK under fair dealing exception (aka fair use). IANAL, but I would be surprised if it's any different in the US. 

Obviously, if you republish someone else's papers in full, this is anything but a blog.