Is possible to assign shortcuts to brushes? In Photoshop I can do it with a macro, and the macro accepts shortcuts.

In reality I want a shortcut for the eraser, the equivalent to a shortcut for a brush. The current eraser has the same characteristic than the current brush, something that is cool sometimes but not when doing fine line.
I have noticed a older talk about the possibility allowing the eraser mode to have a different size. That is not ideal as it would need to be set always that you change to a different brush and also it is not yet present in the built. But the best for me would be simply a brush shortcut.

I know also that is possible to swap with the last brush using /, but again if you change between different brushes you will lose the eraser and needs to be set continuously.

Well, this is largely the reason the pop-up palette was designed: so you'd have your favourite presets right at right-click.

We are still discussing shortcuts: the largest issue is UI and which hotkeys we should reserve for shortcuts.