A few questions...

Currently debating if that menu should be available globally (on every page) from a menu item in the header if you're not on home. I don't know how much I'd use it. I sort of explored having it be a single "Favorites" that you could have everywhere and modify anywhere. But it might make more sense to have a simple home sidebar and a separate "favorites" to replace the quick create menu.

As a thought, it might be nice if Administrators could pin other items to the menu bar, not just Repositories and Projects. For us, it'd be nice to pin a "Developer Enchiridion" wiki page to the menu bar.

At least as a default anyway (with people being able to change what's in the sidebar for them). This could be driven through the settings / roles stuff?

It's one of the most commonly used symbols for favorites these days. Do you have a better suggestion? I think "bookmark" is less recognizable, and this is no longer strictly a create menu.

its not about star being used for favorites so much as being used as an 'action' menu.
I'd expect a "gear" (a la gmail) or something similar. Pressing the star would make me think I'm flagging the current page in some way,

That is my intention, yes, to be able to easily favorite the current page.

A gear icon says "mechanics". Even in gmail it's about the mechanical display of the content, not a set of favorite content.

You can search sites like Dribbble for "favorites" to get a better idea how common star and heart are being used these days. I suppose older people might more easily recognize "bookmark", but like "flags" that gives the impression these are temporary items, and not "favorites" that you will frequently visit.

This is all a bit of bike shedding anyways, these are concept explorations about function, and not final form.

Ah, so clicking the button will add the page to the menu? I didn't realize that. A star is fine.

I thought it was an expanded version of the existing "+" button with a fixed set of items.