Seamless switch from WordPress.com to ww.wp.xz.cn

Unable to find clear answers to my question selsewhere on the forum I decided to take the effort of asking them myself.

In short, I’m tired of the restrictions in WordPress.com where I currently have a blog. So I want to switch and ww.wp.xz.cn seems like a good alternative because I already have my own host server.

Now, on my WordPress.com blog I’ve always used my own domain http://www.anderstornvig.dk and my questions are:

• Assuming that I keep the exact same link/permalink/friendly-url structure on my new ww.wp.xz.cn blog as WordPress.com uses now, and export/import the content, etc., do I have to remove my WordPress.com blog to keep Google from registering duplicate content between the two blogs?
• And can I safely do this and still keep external links to my blog from other blogs intact?
• Does ww.wp.xz.cn by default make identical links to the ones WordPress.com uses?
• Finally, will any of these changes affect my PageRank, SERP rank, etc. when I’m going to use the same domain?

As you may have seen, I aim to do a completely seamless switch from WordPress.com to ww.wp.xz.cn, both from Google’s point of view, other bloggers’ and my own, and any advice on this in general is also appreciated.

Thank you.