Hi,
1 & 2. Since HikaShop 2.6.0 ; the menu/module edition has been moved into the Joomla part.
So when you will edit your module or menu in the Joomla interface, you will find new tabs for the HikaShop content.
The "old" interface is still available for Joomla 1.5 and 2.5 ; that's why the documentation is still available but we are working on a new one for Joomla 3.x
3. It's not a product listing menu ; it's a category listing menu with a product listing module.
So you need to deactivate "show image" and "show description" in the "category options" tab.
4. In the HikaShop configuration, under the "images" section.
5. Helix 3 is using Bootstrap 3.
HikaShop is compatible (for the moment) only with Bootstrap 2 when you activate the "bootstrap design".
6. Your overrides are made using the Joomla override system. So the data is stored in a specific folder in your template and you won't loose you modification with updates.
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.