Can you add notes to a PDF?

Not sure where to post this query, but when I create new notes when annotating a PDF I am finding them impossible to delete. The interface is such that everytime I click within a file, a new note is created. I had some success highlighting the notes then using cmd-delete to get rid of them, but it only works sometimes. Is this a bug or, more likely, something I am doing wrong?
On a separate note, would be great if you could highlight within PDFs.

To delete notes you need to select the tool icon for the thing you want to delete, either a note - in a balloon - or a text field. Then, hover the cursor over the existing note or text field you want to delete until the cursor turns into the hand cursor. Click inside the thing you want to delete, then press the delete key.

Select the text you want to highlight and use the highlighter tool.

If necessary, customize your toolbar to add this tool set.

Is there a way we can make use of the Annotate toolbar in DT pdf viewer by menu or keyboard shortcut (ideally) or contextual menu (by right clicking on the pdf)?

Isn’t it a bit hard to use the toolbar buttons on the PDF viewer. When I use “full screen” on the PDF, I am only limited to the Highlighter.

I am aware of I can do Highlighting and Note etc. more easily with Preview and Skim. But I find staying with DT as much as possible reduces distraction.