Hi,
Sorry for the late answer :
1.
a. So the best solution will be to set the "Hide wishlist button for guest users" option to YES, through "Hikashop->System->Configuration->'Features'"
b. That's maybe a cache issue, can you disable the Joomla cache, and clear it ? You'll also have to disable it in the joomla config, and unpublish the cache plugin. Also can you clear your browser's cache and try it again ?
2.
The file to edit will be the "cart" file of the "product" view of your front-end template, through "Hikashop->Display->Views".