what theme did you start with when creating the custom theme that is applied t your store?
looking in the webassist/themes/SilkPlantsCanada2/css/default_styles.css and webassist/themes/SilkPlantsCanada2/css/default_home.css files, there are a lot of styles with padding and margin settings that do not exist in the default theme files:
webassist/themes/default/css/default_styles.css and webassist/themes/default/css/default_home.css
I think these extra passing and margins are causing the display problems you are experiencing.
for the items showing on the results page in the wrong category, add this info to the ticket for your admin settings issue and we will look into it along with the admin settings.