We are excited to announce that we have launched our new Hive Community! HiveNation will remain as an archive, but all new posts, discussions, and articles will be created on Hive Community. You can visit our new community at thehivecommunity.aerohive.com
Unfortunately, the only options for modifying a template are going to be what you see on that page; the ability to use a custom icon, custom logo, and description text. If you'd like more customization options available, I would recommend using the feedback option on the right hand side of the page to request these features.