It’s a great question, and I look forward to seeing if others have suggestions, too! We publish InDesign Magazine as a PDF at 1024 x 768 pixels, and set image resolution to 150 ppi.

While plug-ins rarely work across versions, scripts often do. But you typically just have to test it to see if it works. If it fails, it will probably be obvious (giving you an error alert).

Here is some more information, specifically about scripting tables: https://creativepro.com/tackling-tables-through-scripting.php

Chris’s table solution might work, but I think Matt’s GREP idea is faster and easier. But I think I would use:
Find: (^\d+$)\r(^\u+?\d+$)
Replace: $2\r$1

Make sure you have not applied formatting to the text first, because GREP find/change like this will mess it up.

No, sorry, I don’t think that it will be recorded.

Are there specific things you need help with? One of the best ways to learn scripting (or any programming) is to “steal” other people’s scripts and then make small changes to them. That often gives you a sense for how things work.

You saw Keith’s article here?
https://creativepro.com/learn-to-automate-indesign-by-scripting.php