Thanks for all the great work on Affinity Publisher so far.
I have a couple of suggestions.
Guides manager. Please make column guide settings for style and colour sticky - either saved with the document or (preferably) persistent until they are changed again. Also, I think the guides manager would be easier to use if the columns, rows and gutter fields had steppers rather than pop-up sliders.
Drag and drop text editing. I'm a subeditor and many of the last-minute changes made on publications are quicker with drag and drop.