Hmm. I believe you can click on the text field under the chat to get its focus back, but yes, every time you click to craft, it will lose focus again.
It's a question. Should keyboard control (Tab, Enter, etc.) work on in-game windows at all? I think it's nice when talking to NPCs to be able to scroll Up/Down. But the downside is chat.
Or another approach: should it work the other way around, where the keyboard control only works if the chat is empty, but keystrokes first go to chat?
Thoughts?

The traditional way it works is Enter will always engage the chat.  Yes, there are NPCSs that benefit from using Enter key to interact, but I would argue all those cases are due to problems with game design(i.e. having to have many repeating interactions with an NPC to sell the same item in small quantities).

I seem to recall you mentioning, like 100 years ago, that you would be implementing lua scripting to the game.  I believe this would resolve many of the work-arounds GMs employed for NPC interactions that benefit from spamming Enter.

Another thing that seems to throw me when interacting with the UI is how ESC works.  Generally, when no windows are open, ESC will toggle the menu on and off.  When a window is open(inventory, for example), ESC should close the top-most active window.  I find myself frequently fighting those old habits in this game.