I leave in Brasil and I intend to buy Nero MediaHome 2015 Unlimited. Will I have to renew the signature and pay for it every year? Is there somebody in Brasil who I can write my questions to?
No, you don't have to pay for a subscription every year. There is one-time payment available which means that you can install it many times after the payment is complete.
Use the following URL to access the buying page: http://www.nero.com/eng/products/nero-mediahome/why-download-nero-mediahome.php
Secondly, you can use the Support section to get in touch with the actual developers of the software. You just have to make sure that the Internet connection is stable and the Nero website isn't blocked by the ISP.