Did you see the customizations library linked from the top? It's kinda incomplete right now, I guess; if you're missing things, you can request them on the talk page and I'll add them.

http://usability.wikimedia.org/wiki/Toolbar_customization/Library

I saw it, but most people don't want to edit JS files.

I imagine a tab in preferences, where the user can check which buttons he wants to see in the toolbar.

In the toolbar itself you can put a link called "customize", which leads to that page. (In desktop applications with rich toolbars such as Firefox or OpenOffice it is usually done by right-clicking, but this is not common in websites.)

(In reply to comment #2)

I saw it, but most people don't want to edit JS files.

I imagine a tab in preferences, where the user can check which buttons he wants
to see in the toolbar.

You could implement these extra buttons as gadgets very easily.

Yes, but they shouldn't be done as gadgets. Gadgets are usually implemented separately in every project. This looks like something that is basically useful for everyone. In English, Russian and Hebrew people complained about the disappeared strikeout button, for example.

(In reply to comment #4)

Yes, but they shouldn't be done as gadgets. Gadgets are usually implemented
separately in every project. This looks like something that is basically useful
for everyone. In English, Russian and Hebrew people complained about the
disappeared strikeout button, for example.

Could implement a few popular ones as preferences I guess.

*Mass-change: Move WikiEditor bugs to component and remove blocker bug where*

mhershberger wrote:

Unassigning default assignments. http://article.gmane.org/gmane.science.linguistics.wikipedia.technical/54734

This seems duplicate with T27068: Non-technical way to customize the WikiEditor editing tools