How can I batch open the content of layers 1 to 4 and hide all the content below layer 4?
Unfortunately, you may only either open one level via ctrl+down or all levels via ctrl+shift+down.
Thanks, I wrote a feature request for that, 
. I think this is kinda necessary 
.
Another small question, do you know how to change the formatting of a layer in bulk, add expressions or colors to this layer in bulk?
Only via selecting all the rem (use drag-select or zoom into the level of interest and keep pressing ctrl+a until it selects everything or shift+up/down to select above/below), then using the appropriate hotkey or omnibar command for formatting. Not sure what you mean by adding expressions, though.
I mean adding emoticons for specific tiers in bulk. That way as soon as I see the emoticon next to the title I know the level it belongs to.
Then use the appropriate hotkeys or omnibar command to format it, unfortunately I don’t know how to follow this phrase accordingly.
Also impossible at the moment, see (emojis are references)