12 This is unrelated to using lists, the same happens with normal text and anything else. If used without any options, `columns` changes the margins to 0pt and then add an hfill before, between and after the columns. You would need to take into account the hfill between the columns when calculating the width of the columns that would give the same space in front and after the columns as the margins of normal text.
6 As @Marmot already [mentioned in the chat](https://topanswers.xyz/transcript?room=1507&id=78903#c78903), it is a known limitation of pgfpages that links and similar objects will stay at their original location. This means you can work around the problem by making sure that the page with the links/forms/etc. does not need to move
5 Here is a proposal. You can add and remove elements from the list of edges with the pgf keys `add edges` and `remove edges`, respectively. Since you are saying that you want to draw the result each time, this is built into these keys. Adding and removing is achieved by steering the visibility via `overlay-beamer-styles`.