don't think you've noticed it but show/hide collections panel already has a shortcut, it's displayed in the ellipsis Edge menu: Ctrl + Shift + Y
shortcut for adding current page to collection is a bit confusing, because when you right-click on a page and add page to collections, you have to select a collection first, so the shortcut could only show the list and you still have to manually select the collection.
I don't find the shortcut for starting a new collection useful, because most of the time I'm adding content to a collection, not repeatedly creating collections.
collections are like notebooks and items in collections are pages. I often add pages to notebooks instead of creating empty notebooks.
anyway, for the other 2 options, you can send them as feedback using feedback button on Edge or (Alt + Shift + i) shortcuts. it's the primary way Edge developers receive suggestions/feedbacks.