DNS Hosting' is a special case and means the following:
I have a domain registered somewhere. I want to use your DNS servers for my domain but I do not want to transfer my domain to your registrar. I buy a DNS hosting from you. A zone for my domain is created on your nameserver, I got an access to the web interface which allows me to manage this zone. But I still have to change a registration data for the domain myself (define your nameservers), and I still have to pay for the domain myself. It is a simplified situation - it is not possible to buy a DNS hosting only, this option is available for me when I'm buying something else - VPS or a plesk shared domain for example. For this service a fee is charged.
If I'm buying a new domain through your store - then of course HSPcomplete will create a subscription for this domain and will raise renewal orders. The same is true for domain transfers (BTW if I buy a DNS hosting from you - later on I can use 'transfer domain' option and in this case, after a domain has been transferred, HSPcomplete creates a subscription for it and generates renewals).