Icon text, how to? Collapse/according hierarchy?

Hello, i’m starting to use this plugin and so far it’s solving many of my problems, i like it!

Sorry if i ask two questions here:

– icon text? i can’t find what codes i should use in order to use icons.
– my tree of categories and subcategories is quite large. I like the field groups toggle-able but:
— not having the checkbox makes it less intuitive.
— is it possible to toggle all parent categories in the tree to make it “smaller”?

It was 3 questions in the end

Thanks in advance