Hey @r2d2, thanks for feedback, few comments:
You can actually use 1,2,3 keys on keyboard to switch between those tools, even easier as it is very common place to have your hand around.
You think that combobox "Filter" does not suits your needs? By the way you can hold-click to select options there.
As number of types of assets grow and will grow in future, it won't be possible to fit them in a bar as they used to be before.
There are many ways you can do it, by clicking on picker, or by dragging asset onto slots you want it to be assigned to.
@redka, thanks for feedback
Yes we noticed that tiny issues with scrolling in inspector with preview, will have a look at that.
Thank you a lot for detailed reproduction steps, that is very useful.
@Detzt, multi-selection is in development, so it will happen