Nice! What u trying to do with it? Gonna waterproof it?

That is the point of the build, to have the battery and electronics protected.

First, there is no video so no VTX heat. ESC has passive cooling from the box, i have no problems with temperature during flight.

There is no video. Yes, the photo is taken after a crash. The arms are heavy, but very stiff, it does not seem to vibrate and pid is easy to tune.

The box looks like unnecessary extra weight. Why have it?

VTX and ESC usually rely on significant airflow over them to only get hot and not just catch fire. Did you install any cooling or heat sinks (or heat pipes)?

Cool! How do you manage VTX heat? Or no video?

One of those arms looks bent. How are those metal arms for vibrations?

Does it fly?