As far as intuitiveness is concerned, most of my problems are with the image editor and animations right now. The animation tab really shouldn't exist, and there's plenty of room in the image editor for all its functions that right now doesn't seem to do anything. Right now you have to close an image then switch from a more useful tab to "animations," make a new animation that AFAIK you can't rename, then open it (Which also opens the first animation for some reason).
There are too many things in general which make you close out of windows to change, such as object properties while in the event sheet, even though there's still a big list of objects to the side which stop functioning like they would in the layout editor.
As far as the tabs go, right now I use "resources" as a dummy tab (Because right now none of its features seem to work) to keep the main window from resizing, then drag out each of the other windows so they can stack vertically. Otherwise it's too much of a break in pace to switch from "project" to "layers" all the time. I wish you could use some of that massive blank space to the right of the ribbon, as well.
As far as the image editor is concerned, it's probably just a work in progress but there's a few things worth mentioning. The eraser tool is just the brush tool set to transparent. It would save huge amount of time letting the user just select transparency with the brush, especially with Ctrl+Left click. Image points cannot be ordered or deleted. They are always alphabetical. If I want to use them in a formula I have to preface them with 1,2,3 etc. If I get the order wrong I have to replace every single one; and with both image points and hotspots, you cannot enter text coordinates so this also makes it more difficult.
It's also very difficult to get a tooltip on an object to show up. It seems to show up once per click, then disappears forever when you move the mouse at all. The tooltips, being the only way to tell which layer an object is on, also start being a problem when they tell you every object is apparently on layer *?*. Probably just a minor bug though.
I don't mean this as a negative rant. I love construct and it's awesome. These are just some observations. Much respect to the work you guys have done.