Hi,
The footer where the HikaShop text is displayed can be removed by turning off the "show footer" option of the HikaShop configuration.
Having the ids and class names in the output HTML/CSS/Javascript is necessary to avoid conflicts with other extensions. With thousands of extensions out there for Joomla which can be used on the same website, that is a necessity.
Yes it tells hackers that you use HikaShop. So what ? There are many ways you can tell which extension/application is used on a website, even without that. Show me a website and I can tell you if it uses Joomla or not, even if you try your best to hide it and even if the id/class names are not prefixed with "joomla". For example, just add /index.php?option=com_users to the domain name of any website like
www.joomla.org/index.php?option=com_users
and if you get a username/password form, you know it's a Joomla website. Then, if you go to
www.joomla.org/index.php?option=com_hikashop
, you'll get a 404 error if HikaShop is not installed so if you don't get that 404 error, you know you have HikaShop on the website. That's the same for any Joomla component.
Any hacker worth its salt would be able to do the same and much much more. And similar methods can be used for other ecommerce/CMS out there. Real security is not about obfuscation, it's about designing your application to be secure:
en.wikipedia.org/wiki/Secure_by_design
Now, if you want to change the ids and class names to remove HikaShop from them, it's not impossible. HikaShop is completely open source and you can override all the views of HikaShop. But that's a incredible big development, which won't help you be more secure.