Draise, don’t panic, i am an artist too, you know 
You have the same tabbing / clicking with the add menu in Blender. Just that you don’t click at a tab here, but a sub menu field. And this with every new node you want to add. No difference. And the text menu disappears when you click a menu item. Again press hotkey, again go through the sub menus. While the tool shelf stays open. As told, it’s imho the worse solution. Even with the menu popping up at mouse position.
A double menu entry is when the exact menu item is at another location of the UI too. And that was the case with the add menu and the buttons in the tool shelf. I will not reintroduce such double menu entries. I will remove them where ever i find them. One menu location is already hard enough to recognize with 2400 available operators.
Different story with the toolbar at the top, this one is user configurable. And contains as much of the already available menu items as possible. Unfortunately not the nodes. Technically impossible.
But let’s have a look at the real problem: What is missing is a useful structure to reduce the searching and tabbing. The Blender structure is that they categorized the nodes by alphabet and grouped them by what they are doing. Not how you USE it. There is no guidance through the process. And so you tab and tab and tab. In search for the nodes that you need. Which are alphabetically somewhere in the middle between the nodes that you never ever use. One tab for math, one tab for image, one tab for … ah where was the texture node, where was the normalmap node … . And you go crazier the longer you try to work that way. That’s the real problem that i see here.
I think i have a solution. Which will reduce the available tabs to three. Maybe four. And may bring the needed structure to reduce tabbing and searching to a minimum. I will tweak the nodes icons panel addon for that so that we have a prototype to toy with. It may need some time though 