Will the app loader and IDE get a UI update?

having the possiblility of the loader site to connect to webide emulator and install apps/widgets there like with real device could be nice too.

This is very possible and would be a nice addition. The only downside is the app loader would have to load the emulator window itself, so you wouldn't get the IDE running at the same time.

BTW if you like VS Code maybe making vscode plugin would be better option than redesigning the IDE?

Yes! If your complaint is basically that the IDE isn't Visual Studio code, then just using VS Code seems like the best option for everyone.

You can just use the CLI, but it can end up being a bit of a pain to get it working (Bluetooth LE support in Node.js is fine on Linux and Mac OS but is very painful to get working on Windows). If you were able to make a plugin for VS code that effectively launched the Web IDE (just as a terminal) in a separate window then we could use all the Web APIs (like Web Bluetooth) and it would 'just work'.

... that would be a massive benefit for loads of people, especially those already using VS Code