You can't just change your hostname in /etc/sysconfig/network and just expect the hostname you've picked to propagate through the whole DNS database! Your ISP couldn't care less about what your OS calls itself, nor do upstream DNS servers. Not only that but .alleyway isn't even a valid TLD
Most ISPs divvy out IP addresses via dhcp. And for many of the big ISPs, the WAN hostnames of clients actually incorporates the IP as part of the WAN hostname (this is especially true of ISPs that serve large numbers of customers). Whatever naming and addressing scheme your ISP use, you likely won't have any control over it unless you sign and pay for a business service plan.
Either contact your ISP to get a static IP and associate it with a domain you've registered, or try a service like DynDNS.org (I think DynDNS still has a free, if crippled, account option).