As for the windows (I think you talk about panels -> https://tilepieces.net/documentation/UI/panels.html) they can be set right, left, above, below (they are fixed below 1024px).
They are certainly a bit .. rough/raw/sketched i think you could say... as everything to the UI, but at the moment I think the important thing is that they work.
The third point you are referring to is a bug! I swear it worked until yesterday :)!
Is there a reason to have that functionality exist in the same view? It feels like the benefit of a window ("panel") based UI is that you can dedicate each group of functions to one window and not need to combine different jobs into the same panel.
Because projects and components go together. After creating a project, you can use components in its HTML pages. So I think it's best to put them together. You can find pre-made components in this repository https://github.com/tilepieces/component-examples/
Where possible, I try to put the related features in one panel, as too many panels can be confusing (even in the developer's mind!).
Anyway, if you have ideas for improving tilepieces, I have opened a "new features" category in the github discussions (https://github.com/tilepieces/tilepieces/discussions/categor...). I will gladly listen to them.
Is there a reason to have that functionality exist in the same view? It feels like the benefit of a window ("panel") based UI is that you can dedicate each group of functions to one window and not need to combine different jobs into the same panel.