Good tips for br in p
I would like to add one suggestion on a, try to avoid using target=_blank as it breaks the flow of browsing way more than use of #
In general, like you said, if you need to use only # fro href, try to use button but it is useful as jump to top of page can just be achieved by using # as href
Buttons need more style resets than links and probably that's why I would go for using a[href="#"] as having click handlers on text nodes is less recommended