Can I create a link from one entry to another?
Indeed you can! In the sheet for editing links there are two new buttons: one for linking to an entry and one for linking to a file. Clicking the latter will bring up an open panel to select a file on disk and clicking the former will bring up a different kind of open panel: it will show you all of your journals and entries and you can select the one to which you want to link. These are just assistants; you can still just type in the URL manually or drag an entry from at? drawer or a file from disk into the URL field to paste.