Earlier it was posted here by a member of staff that the R1Soft Backup is currently unavailable. http://x10hosting.com/forums/free-hosting/119193-my-wordpress-blog-has-become-corrupt-after-domain-change.html#post671811
You seem to have the same problem as this other user http://x10hosting.com/forums/free-hosting/119159-urgent-addresses-dont-work-subdomain.html. This user found a solution that worked.
Like I said, try rebooting your computer since it's not one of the things that you've done yet. Sometimes that's what my computer needs when it's having internet connection problems.
I honestly don't know. Since other people including I can see your site just fine, the problem just might be on your end. Try calling your ISP to see if something is wrong with your internet connection or call tech support for your Macbook.
Edit: WAIT. Have you rebooted your computer at...
The 404 errror might be fixed if you flush your DNS. The instructions were already given to you in the comments of this post.
Then type in the terminal the following:
Press enter after typing what applies above to your OS, and restart your browser.
The account didn't get created because you still had an error. Log back in, clear the sign up attempt, stay logged in and then try to sign up again. Hopefully it'll work this time.