@ph4wks I’ll try to do a TL;DR: type [[file I want to link to# and you’ll see a list of headers to include. Typing [[file I want to link to#^ will give you the blocks instead. If you add a bang right before ![[file I want to link to#a header]] the contents of that header (or block) will be visible in preview mode.
I recommend checking out the official docs to get a better grasp. I recommend checking out the local Help Vault, so you can see the syntax, but here are the publish links for quick reference:
Finally, take into account the advice by @I-d-as. You can support this feature request for propagating header changes: Auto-update links to headers on header title change.
I’ll move this to #resolved-help in the meantime.