I also have switched to a self hosted blog, and would like my followers/subscribers to be transferred.
Old site: thebigrisk.wordpress.com
New site: thebigrisk.com
We can only transfer email subscribers from your WordPress.com blog to your self–hosted blog since the rest of your WP.com followers are following your blog through Reader.
(They can follow your self–hosted blog through WordPress.com Reader by clicking Edit List next to Blogs I Follow.)
If you'd like us to proceed transferring the email subscribers from your old site to new site, please reply to this forum thread.
is it possible to transfer site stats (views, top stories, etc)?
No, I'm afraid not. Sorry for the inconvenience.
is there a possibility for me to deactivate the old blog, or stop readers from going there?
You can permanently delete your WordPress.com blog in Tools -> Delete Site in your WordPress.com blog dashboard.
Or, I'd suggest the Site Redirect upgrade to automatically redirect visitors to your new blog (thebigrisk.com)
How do I get email notification that someone subscribed to my new blog?
With Jetpack, we don't send email notifications when someone subscribes to your blog.