- How can I edit URL in Edge favorites?
- How can I add link from page directly to favorites?
Unfortunately it seems that currently the answer to both of your questions is, you can't.
It's not possible to edit the URL of a favourite. As a workaround, you can open the favourite, change the URL in the address bar, add that back to favourites and then delete the old one.
It also doesn't look like you can add the target of a link directly to favourites (though you can add it to reading list). You'll have to open the link, then add the opened page to favourites.
If you need this functionality, you may want to let Microsoft know using the Feedback Hub.
You can use tools like Edge Manage in PC to edit bookmarks, folders, etc... and sync them back to your phone. This may be a bit of work but it provides additional functionalities like local backup of bookmarks. Although it requires the use of a PC it may be highly useful when you require to edit in bulk.