Hi,
You can manage your subscription and the website attached in the "your subscription" page.
There is no problem to install to another domain but only one will have to automatic updates (and the other services) attached.
And if you domain changes, you can change it too in our website.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.