Quote Originally Posted by robax View Post
If the ip was blocked, would I be able to access the Zen cart site at all from the server?
No, you couldn't.

Quote Originally Posted by robax View Post
If that page is accessible from the server's web browser, then does that mean it should also work via curltest.php running off the same server/ip?
Yes, it should.

Quote Originally Posted by robax View Post
Or is the curltest.php using a special port that I could check for. I've read that it wants 80 or 443 and as far as I can tell they are both open both ways.
It's using port 80 for non-SSL and 443 for SSL, which are normal web traffic.

28 => Operation timed out after 4 seconds with 0 bytes received
Your hosting company is going to have to sort out whatever is causing the timeout problems.