Specifically, could I somehow make disappear the […] (cloze) icon?
(I don’t need most icons since I prefer keyboard shortcuts)
After installing another, very useful addon, which, unfortunately, is adding one more unneeded icon:
My editors have to be a certain width (I can’t widen the Add-window any further), all the icons just about fit onto one line … until I select a cloze note type with its additional icon 
This now makes all my fields jump down one line (and later back up again), which is annoying …
PS I’m a complete noob, but I might try this:
Hide editor elements (by id, class, CSS selector)