What Pierre said! Unlike the bad old days we've got things like AJAX, REST APIs, and jQuery so it's probably a lot easier to add, remove, and configure toolbars than it was way back when.

I love the idea of putting the style dropdown on the top line (minus H1.)

The only button I'd categorically take out would be Underline. I would be extremely grateful if H1 was pulled from the style dropdown.

I think it would be fine to move left, right, center, and justify to the second row. I think it would be a shame to lose justify, which I agree can look really bad in English but seemed to work nicely on one of my Chinese client's sites.

Perhaps I'm the only one who uses erase all formatting but it comes in handy when pasting content from other apps and sites.

Going back to what Pierre said, just because I have use cases for justify and erase all doesn't mean everyone should be subjected to it. But I'd be sorry if I couldn't easily put them back in. Does anyone know if there's an AJAX button editor for TinyMCE?