Found a workaround for Q2.

Steam Store has a tab heading titled “Recently Updated”, in it you can find a section called “Recently Updated”:

https://store.steampowered.com/news/

This is comparable to your news feed in your library but it also includes news/updates from games that you have on wishlist. Not the most elegant solution, but it does limit the number of items compared to AnarchoNoAdjectives “/updated/all” link.

Thank you so much!

Perfect solution for Q1!

For Q2, does anyone have any thoughts about filtering all updates either by tag or by a specific game list?