Suggestion 1 is covered here: https://forum.obsidian.md/t/automatic-inline-update-of-links-to-headers-when-they-are-modified-no-extra-dialog-window/25412
Suggestion 2 is covered here: https://forum.obsidian.md/t/add-markers-in-the-gutter-for-headings-and-blocks-that-are-referenced-somewhere-else/37708