Total Commander

After installing an impressive "power menu", I have found myself somewhat lost in the sheer number of options.

Would it be possible to add the quick finder for the menu items? Like in OS X, latest versions of Libre Office and multitude of other applications on different platforms.

You can use command browser, it is not a menu search but if you defined all menu/alias/hotkey entries as user command, you should be able to find what you want.
Having huge Menu is good to explore but to be more productive, you should just focus on what you need for everyday work with bars, hotkeys, ... and even use dedicated entries in Directory Hot List to store useful folder but also command.

I also miss searching and locating items in the menus, so support this request.

I have most used commands on keyboard shortcuts, less used on buttons in the bars and those least used are in the menus. So often I find myself wondering where in the menu is some command.