To execute osc_run hook ('my_hook) alone must be placed inside theme file or your plugin to have a dedicated page available where you can place your hooks .
There is no way to execute osc_run_hook('my_hook') from your plugin in the middle of item page for example without hooking into an already existing hook., or site admin to edit that page manually and write osc_run_hook('my_hook')
You cannot fire the hook inside the plugin by finding the current 'action', 'section', page, becouse your plugin maybe is loaded among first and not all the plugins are loaded.
The situation changes if is a theme or a plugin page
Inside your theme item file or your plugin dedicated page you can place hook after hook with no problem ..
osc_run_hook('my_header')
osc_run_hook('header')
osc_run_hook('after_header')
Just keep the well known hooks becouse some plugins do hook there and removing them will damage some functions.
A theme is the owner of the layout , plugins just brings some features following the theme rules or complement it by adding new pages .
A plugin acting like a man in the midle ,catching the request (item page )and redirect into a item page clone inside your plugin cannot be done becouse you cannot guess the current layout . (Bootstrap theme,bender,etc).
Just as i said in the first post ,your hook must be triggered inside a well know hook for well known pages (main,item,user ,etc) or site admin to write by hand as many hooks as he wants into that files .