I have a wordpress.com account and that API key does not seem to work. Checking my error log doesn’t reveal any errors from any time I try to enter my API key, too. Same goes with the dashboard, I don’t see any errors in the log file. As for posting by email, I did notice some errors in the log file about being unable to connect to my POP3 server when I had the wp-cron plugin. Going to wp-mail.php in my browser resulted in the same thing.
The slowness is also very bothersome. Attempting to log in or to get to the admin part of the site is very slow, usually taking 1 to 2 minutes to get there.
This is all baffling me since Drupal worked fine on my site (except for constantly breaking when upgrading) and generally my ISP seems to have stuff setup pretty well.