Experiencing multiple error messages in various pl

-- url of the page with the problem -- : www.Airsoft-hq.co.za
-- HikaShop version -- : 2.4.0
-- Joomla version -- : 3.3.6
-- Browser(s) name and version -- : Firefox 39.0
-- Error-message(debug-mod must be tuned on) -- : Strict Standards: Only variables should be assigned by reference in /home/airsohdr/public_html/shop/components/com_hikashop/views/product/tmpl/compare.php on lie 12
Notice: Use of undefined constant JPATH_COMPONENT - assumed 'JPATH_COMPONENT'in /home/airsohdr/public_html/shop/libraries/legacy/view/legacy.php on line 166
Notice: Undefined property: stdClass::$product_parent_id in /home/airsohdr/public_html/shop/plugins/search/hikashop_products.php on line 324
Warning: in_array() expects parameter 2 to be array, string given in /home/airsohdr/public_html/shop/plugins/jevents/jevjcomments/jevjcomments.php on line 19

Strict Standards: Only variables should be assigned by reference in /home/airsohdr/public_html/shop/components/com_hikashop/views/product/tmpl/compare.php on line 12 - experienced on log in page

Notice: Use of undefined constant JPATH_COMPONENT - assumed 'JPATH_COMPONENT'in /home/airsohdr/public_html/shop/libraries/legacy/view/legacy.php on line 166 - experienced on an email confirming order

Notice: Undefined property: stdClass::$product_parent_id in /home/airsohdr/public_html/shop/plugins/search/hikashop_products.php on line 324 - experienced on search page for only certain products. Appears numerous times (1 less than number of search results returned)

Warning: in_array() expects parameter 2 to be array, string given in /home/airsohdr/public_html/shop/plugins/jevents/jevjcomments/jevjcomments.php on line 19 - experienced on a Jeventsevent page